Don't know if anyone has posted this yet, but I just got an email from Fitness Fly. Apparently they are offering a $4 credit for certain used DVD titles. After shipping it to them and taking into consideration their DVD prices/shipping fees you might have to work out if it's worth it or not. Unfortunately I don't have any of the titles they are looking for...
https://www.fitnessfly.com/articles.asp?id=123&Click=1059
https://www.fitnessfly.com/articles.asp?id=123&Click=1059