Pricing fabric can be a tricky thing. There are a couple things to consider: where the fabric was purchased, how much you paid for the fabric, and quality (lesser quality fabric can be purchased everywhere). You want to get the most $$, but still be able to sell it. I would think most times, you could sell it at half the price you paid....but that would also depend on your area and how many quilters you think you could get to look at your fabric. Books and patterns I would price at 50% off retail for anything in good shape (I can buy used books at Amazon for 50% off). A well used book/pattern with dog eared corners and writing I would price at 75% of retail. There are simply lots of variables to pricing quilting things....no clear cut answers.