I just sold a ton of books from my old appraising business on ebay. Prices were very inconsistent. I would try here and see how it goes first - then try some of the other options if you have some left.
I shipped everything media mail...outside of one that got sidetracked they all made it to there destinations in about a week. Shipping through Paypal (if they pay that way) includes delivery confirmation so you can see that it was delivered and when. If you don't use Paypal then you have to take it to the Post Office to ship media mail or 1st class. Priority you can do online. Hope that helps a little!