Berendol has a nice server and that has given me a few ideas.
He has made destruction scrolls available and a few more things too.
Consider being a priest!
What makes a priest a priest? Healing I say, but as Healing potions are stocked at shop 7.
Potions and scrolls are more reliable than any spell. And every spell a priest has can be bought or found.
And if everything is available then everyone would be Warrior as they get one more blow, or Rouge for speed, etc.
With destruction scroll available why not become a warrior? Why not use it as a mage?... you get less fail.
On rohnan, my mage Nannif is buying restore mana potions for 30k and *healing for 50k and Life for 100k. There not commonly available in store, and not expensive, but very valuable to me.
OK. That's the description of the problem, now to a solution !!!
I believe some things should have a floating price. (Most expensive things)
Make all shops 1-6 have a max of 10-30k gold as in original angband. Thus making cash from them would not be so easy.
Shop 7 should not be so random, but should stock what's sold there and everything sold there should have BM pricing, a floating price. Every time you buy a healing potion the price goes up like 5 % and if you can only buy one at the time its very expencive to buy 100 of them. Everytime someone sells a Healing potion the price dropps 5%, and so on. And price should drop with time too (as normal with a shop, it costs to store things). Let the price vary from 1xBase price to 20x base price. And shop 7 should never become full.
Why not make one page with Healing potions and some other always stocked items, and the other page with temporary stuff. Some random and some sold recently, but all with a nice spicing, and all excellent at least.
For Istari, Speed boots etc, its more Individual, I bought Istari for 400k the other day. But I think that's extreme, but 40k or whatever is normal price is really too cheap. If you make shop 7 to only take 1/3 as profit, you will be able to force all players into trading this way.
Mages are the only class that has a spell not available through any means (GoI)
Mass genocide/Genocide should be rare, and so should *healing* as that's sort of trademark for Priest/Paladin
Rare should affect price!!!! BM should offer a lot more than the 5k list price for a Crown of Might +3, as that's quite Rare, and very sought after. 50k is a lot better price.
My vote goes for a system where pricing takes care of itself.