One thing about shopping at the two thrift stores near my house is that even at the ridiculously low prices--averaging $3-$5--there's just not that much that appeals to me.
On the plus side, what a sense of (over)abundance. Anything you might pine for will undoubtedly show up in new or almost new condition. No need to feel deprived.
Also on the plus side is the fact that you will assess your stuff with a new and critical eye. You will see just how little you can get for your items. That's a sobering realization. Might as well donate.
Have you checked out these sites? Have you bought? Sold through or to them? What do you think of them?
P.S. I'm putting together a donation bag RIGHT NOW.