Where can i get the insanity workout dvds and guides really cheap?

I really want to do insanity but i can NOT afford $120 right now (I just went shopping for clothes hehe) and I really need it to be $20 or less. Don't say ebay I have tried but I always get outbid on EVERY single one I bid on which I think is a scam by the way because it happens like 10 seconds after i bid. But anyway please help!