What are the shops with high level items in Skyrim?

I am now at level 32 in the game, and all the items that I can buy from the shops seem like too basic compared to what I find in the dungeons. Are there any special shops with very powerful items that I could have missed?

Solution 1:

Vendors level their inventory as your level increases - and monsters get harder or become different. Harder monsters. Harder dragons. The loot you get from dungeons gets better.

Everything levels up with you.

Solution 2:

A unique merchant, added by the Dragonborn DLC, is the Dremora Merchant. According to the UESP wiki's "Dremora Merchant" article, "At higher levels, he is the best constant source of Daedric items".

Since Daedric items can be hard to come by, it might be worth transacting with this merchant if you're at a high enough level. Since this guy can be summoned almost anywhere, it is easier to buy and sell items from him.