The city's charity "garage sale" of the year was this weekend. We went on Saturday and I bought nothing, but BF and my sister got some good, small things, spending $14 total for an art book, a statuette, some bowls and a case for an iTouch.
Then we went back today. For $3 and a fight with hordes of anxious shoppers, you got a huge cardboard box to fill with anything you wanted. We got two boxes, so for $6: 40 or so books (about 15 fiction, 15 beautiful art books, some with loads of full-color plates, and 10 ordinary nonfiction), plus 2 vintage scarves, a robe and a nice pillowcase.
Some of the used books go for $70+ in the shape we got them in, most for $30+, so I'd estimate the value of the stuff we got at $400+ at non-specialty store prices.