Alibris, too.
I had a book that I had purchased years ago for $7 that one biblio guide said was worth $500 to $650. I used a local antiquarian book dealer for a consignment sale, we agreed to split the money in half. It didn't sell nearly that high, and I kept asking him to take it down in price (he first put it on the market for $550.)
I felt that I needed his reputation for describing condition, that's why I didn't attempt to sell it myself. Condition grading is key and it's got to be a professional assessment for higher end items.
I think that in the end it sold for $225.
