You sound like you're getting burnt out with your players buying stuff, rather than the fact that the magic is available.
My suggestion:
All trading takes place out-of-game.
Items sell for half value.
Items can be bought at book prices, up to a value X, determined by the size of the city, given by the DM when you enter the city.
Totally new items simply cannot be bought (a +x vorpal sword is fine. A ring of cure light wounds is not.)
No haggling will be entered into (ie - institute some flat method for determining an increase or decrease in price based on the appropriate skill).
Players who've bought items will hand over a sheet which shows the cost of whatever they got, and all the working to figure out that price. If it's wrong, you just didn't buy it. Full stop. If it's found to be wrong at a later date, the item will turn out to be cursed and/or faulty. Check your math or have another player check it.
There! Players can now have the gear they want, and you don't have to do the bookkeeping for it. Concentrate on the adventures, and really don't care about what weapons your players have.
If you want something really special, that's called an artifact, or a weapon which would normally be out of their league.
If your problem is more deep-seated than that, then I really don't know what you can do. Start a new campaign set somewhere lower-magic?