Advice on trustworthy audio resellers who check condition, offer trial period?

I'm wondering what resellers you find reputable for your purchasing. I've made three purchases with Tmraudio.com (The Music Room) in Colorado and they've been great. They guarantee their items work, have a 14 day trial period, and an easy to navigate website.

What other sites do you know of like this — not just that connect sellers and buyers, but that take in used gear, test it, rate its cosmetic condition, and offer a trial period? (I'm a bit wary of buying, say, an amplifier of $2k only to find it's not what it's supposed to be.)

This could be a general site, like The Music Room, or just a store that does this (good selection, prices, trustworthy, and trial period). Thoughts?