These are two stores that I have shopped for at least five years now.
My recent Schutz pumps came from Linda's. They give very accurate descriptions of the condition of the item, and the measurements are always spot-on. And usually the shipping is free in the U.S.
Linda's Stuff
http://stores.ebay.com/Lindas-Stuff?_rdc=1
e Drop-Off
http://stores.ebay.com/eDrop-Off?_rdc=1
e Drop-Off has a huge following now, so items tend to sell for more than they used to, but everything I've bought has been top-notch, excellent quality, even pre-owned items. I got a brand new Cole Haan leather coat for $70 a few years back, and that coat has travelled the world with me.
I have a lot of smaller sellers that I follow (people like me, who occasionally list stuff, but don't have stores), but that's pretty random. Usually I just search for an item that I want, keeping the search terms general - such as "black pumps", or, "leather jacket". Then I use eBay filters to whittle down the list to something manageable
When I buy stuff from other sellers, I always look at the number of sales, their satisfaction ratings, and how much description of the item is given, and the clarity of the photographs. I don't buy clothing unless there are measurements given - or unless I know the sizing of a clothing company really well, and know it will fit. Because I always really read through everything, I rarely get burned - but it does happen, occasionally. I never return anything. If something doesn't fit, or I don't like it like I thought I would, I re-sell, donate, or give it to family or friends.