I think the Secondhand Texts and Stationary shop at UQ St Lucia provides a pretty good service to both buyers and sellers of second-hand books. As a buyer, I always go there first to check if the book I need is in stock. Sometimes it is, sometimes it isn't. In fact, I'd say more often than not, I won't find what I'm looking for; you really have to get in early in the semester as popular texts go quickly.
As a seller, I've had a similar experience with this store being a bit hit and miss. They'll only accept books that are "in demand", ie. on a course list for that semester. They have an online registration process at http://www.uqusecondhandtexts.com.au/ that allows you to search your book and find out if it's one they want. You then check a box that says you want to sell that book, print the docket and take it into the store with the book. I'm not sure how pricing works, as they've never wanted any of the books I've been trying to get rid of, but I know that they then put a docket inside the book with your details and the price and once it's sold, the book shop pays you your money.
I suppose you could say they act as a broker, taking the hassle out of buying and selling secondhand books through private sales. It just depends on whether they have what you're looking for or want what you've got, as to whether you'll have a good experience here. read more