The main reason I have heard from Fatnoob for why the prices in the global shop were dropped, and for why there are not a ton of items in the shop, is so that people will go more towards chest shops and therefore those who run chest shops will have a better chance of staying in business.
It helps keep the server going naturally, and the members themselves would get to put prices on all the various items, instead of having to simply go with what an admin deems is "appropriate".