I think that's way too much equipment. The idea area the shops is that you get some rare but unique stuffs. It's not meant to be an all out solution to everything.
Added questions and options for people to consider:
The following two items were put up for consideration on the Mumble, so lets get some more opinions here. 1. Rotten Flesh for Leather We're looking at about 32 for 4 on this, just to make sure it's not too cheap to use as a better alternative to leather farming. Major issue with this is because leather is not too hard to get. This trade would be more along the lines of turning something that's not really useful into something much more useful.
2. Wither skulls We've been getting a lot of complaints about wither skulls being really difficult to get so this is being brought up pretty often. What do people think? Are wither skull hunting in the nether really that hard to actually get some?