I know very few care for what I have to say at any point, buuuuUUUuuuuut... Here is my 2 cents.
There are a lot of valid concerns for many people on this forum post, and all trying to understand the "what for" and "why" of this price hike is only a secondary issue. However, you all have missed the biggest key factors as to what would convince someone to go this direction.
I created an account over 8 years ago, I played for like a week, life happened, and I couldn't get back to it for about 5 years. I come back, and it was during a time of a gradual decline on the population of Excelsior. Fast forward a few years later, and there are a lot fewer players that when I returned initially. At this point, I only knew the existence of +C and +Kimane. I have seen no other +Admin present for over 3 years now.
I've heard stories about how there where tons of Events, and Seasonal Events, but I was not here to enjoy them. Now they are gone, and I am none the wiser. Until I see items for sale on vendors from literally years ago. That is one thing that gave me pause. The second, is the slow pace of Events, and how the holiday events, (Specifically Halloween and Christmas) are better left to players that are far more equipped to fight the bosses, and ask for prices low and mid-tiered players scoff at.
When I goto TC, and see vendors that have the same goods at 9+ to 12 months, still stagnating on them, That tells me the economy is "Not" moving forward, and that a handful of players hold the massive wealth of the server, due to what I would call "Bad Calls" to the game mechanics them selves.
I personally wont do anything more than mention any thing but "Gold Farmers", (no names) as that's a well known, but over looked problem.
There are far more glaring problems that I can see other than accounting, real world inflation, or even the gold farmers them selves.
This is where I get brutally honest, and don't care about the repercussions of my following statements.... Love me or Hate me.. I simply don't care. I enjoy this server, and some of the people. But, if this gets me booted and banned, so be it. I am who I am.
1) You have instant healing with 220 dex. This lopsided mechanic makes the game to easy to play. Or rather "Not" play, which allows "Gold Farmers", provided they have a BoH to hold the bandages, do there farming for endless gold. This means less donations to your server. (obviously)
2) You over powered the Yumi, and Whirlwind Weapons. This lopsided choice to make almost every other weapon obsolete, (except for single target Golf Farming, Crushing Blow specifically) allows less of a play dynamic to your player base. Everyone becomes the same, and Inflation to Weapons to be turned into Yumi or a Whirlwind weapon, due to extremely high demand, becomes a reality. If Whirlwind weapons and Yumi's operated on OSI standard, like they used to, less people would bother with them. I can understand that this was done to garner the purchase of EDs, to Change Weapon Deeds. However, it still creates a problem. I commonly see weapons for 50 to 600 EDs in TC. Yet another thing to chase off new players.
3) The loot table is poor. The strongest, and often wealthier players have access to the better weapon and jewelry drops, and ask for prices most new players would just rather not pay. Again, this hurts new players coming onto the server, and even more so on them staying. No one wants to grind for days, just to pay 200 ED for a 4x46% weapon that's been leveled and placed on someone's vendor. Some vendors try to charge that with none leveled weapons. Also, gold is understandably reduced due to level able weapon deeds. However, adjusting it to where there is almost nothing of value only slows the top tier players down. the Low and Mid-tiered players, suffer. Making grinding not so pleasant, and you lose new players. (Again, less donations for the future. Attendance GOOD!.. Low numbers of players.... BAD!)
4) TC Vendors. You will not be making people go out and play, or actively look for someone to buy there wares, when they don't have to do anything, but gold farm, and throw stuff up there. Not much more I can say, other than TC Vendors operating in the capacity they do, is a bad economical ideal, that's far exceeded its time. It helps drive inflation.
5) Other servers don't allow people to teleport into dungeons, or out of them. Some servers also don't allow someone who has gathers resources, or just finished a fight, to immediately teleport away, either. There are 2 servers I have seen, that wont allow you to bring a mount into a dungeon. It shrinks and goes to your backpack, until you leave said dungeon. Copying this, will change how people hunt, and who comes to your server, and who will stay. (Keep in mind, UOEX, is a copy of someone else's work and ideas. There should be no reason why you have to shun things due to someone else already doing it. If it works, it works. Stops Gold Farming, unless you are in favor of it?)
6) [exex. Is a nice idea, but in the end, makes it to easy for people to "speed along" rather than participate in the game. Put a stone, in the donation room, make a flat rate for EDs, and leave it there. Also allow players to "Sale" to the same stone, so just like with [exex, you have a finite supply. This way no one can complain about it, and donations will still be a regular thing.
7) Donation Room Items. Increasing the price of them is a good way to end up playing "Spin the Bottle", and end up kissing the family dog on the mouth. If you want to fix how players purchase things, don't bother with reducing the prices, or raising them. Make more modes of game play viable.
Give "Mages" the ability to do more damage, if they use a spell book. Put spell book Slayers up in the donation room, and take it out of "Inscription". Make summons harder to dispel, and grant them some more HP than they get summoned with now. (minus EVs) Grant necromancy spell damage modifiers with SDI. Specifically Poison Strike, and make things like Evil Omen useful. "Un gut" Ninjitsu. It's almost the most useless magic skill on this server. Put other weapon specials on the map. Like Armor Ignore from Fencing Weapons. Make the poison "tick" damage on dipped weapons go 2 times faster, or even 3 times faster, and increase the duration a 2-3 more ticks. If you want people to "Use" items, and have the ability to put more items up to be used, then you might want to roll up your sleeves. Or, you could just tell people they need to pay more. (Which everyone seems apposed to.) The possibilities are endless.

Listen to others. Your good at programming, but your not that creative. I know this one will seem unfriendly, but you seem very closed off to almost any idea for upgrading skills, or the server in any way. You run this server like its a office, with cubicles, and a water cooler for a handful to stand around and high five each other, while everyone else (lower level or mid-tiered players) just walk by, with there hands in there pockets and shoulders slumped, and not daring to look anywhere but forward, as they pass the "Cool guys". Thats a uncomfortable feeling for new players, or anyone who doesn't "get with it" to be on your server. Your server attendance is dropping. The creative people (so I have been told), meaning the other +Admin, did a lot, that you don't seem to be capable of. Now they are gone. I my self, as well as plenty of others, have given you good idea after good idea, and some there ideas, even some of mine, "not so good". However, we gave them, and you skirt past them. It is your server, so, do what you want. Just realize that you might want to hear some of the less wealthy players of your UO server, to revitalize it. Because your Gold Farmers, and Auction Hounds, are not who you should be listening to. Thats not gaming. Thats the Forbes 500, UO style. Your forgetting everyone, who will at some point, donate. Often due to lack of patience. (Wanting it now.)
The problem is not money. Its lack of creativity. The most popular servers are the creative ones, that occasionally expand there servers, add new content, quests, items and events. (not just open up portals to champs, and hope you get a skull) None of these servers have relayers, or weapons with a screen full of hit spells, nor do they have infinite skill points. (they often only have 700-800 max) They also don't have infinite healing. Yet they have hundreds of players, and some have over 1-2 thousand players...
You know what more players on the server means? "More Donations" They don't get there player bases, by raising prices, and making things harder to get. Have you seen Pandora? Its a graveyard! The owner of that place did what your starting to suggest now. I have talked to the guy, he is far out there like Pluto... and he single handedly ruined his server attendance. Some of the good servers give the players more to do. Allow more ways to play, which garners diversity. I have started to learn to ignore the fact, that a weapon strike, or a single arrow does so much more damage than a lightning bolt, called from the heavens on a mob does. I'm learning to live with that fact, and it no longer hurts my feelings. Nore do I care about the people who call me stupid for not going straight for how they play. (or rather how 99% of the server plays). I like being a mage, and to tell the truth, I see no issues with the Magery system on UOEX. It could use some upgrades on equipment, but function? No issues.
I will end my opinions, by saying simply this. I like your server, and I do like you (though I don't know you that well), but you seem to be thinking more like a "Corporate Suit", that someone who owns a UO server. To me, this is just a game. Raise the prices, I will stay, lower them, I stay. (unless what I have said here upsets you to the point of banning me) I just derive joy from playing a mage. Its not me you need to worry about. Its those that come here, and leave, that you should be worrying bout. less people, less donations, less money for you. "Period"
Don't let a full wallet for the "moment", cloud your judgement. There may come a time a moth flies out of it. I'm only saying what no one else on your server has the guts to say out loud. Your the +Admin, people kiss your boots, but some times the people you should be hearing, wont do that.. I tip my hat to you sir.... *bows*