Look at it this way. Try listing your DVD's and see what happens. Give them 6 months and if they don't sell, pull them down.

As for your books, there are quite a few book sellers here and while they may not be selling millions a year like some of the big names, they have a reasonable turn over rate. As long as you describe the condition accurately, you should be fine. A lot of people still like real books. I do. I love the look, smell and feel of books. I'll never own a Kindle.

All you can do is try. You aren't going to lose anything by trying.