If you need really cheap ones, call your local Gymnasium...not an exercise gym, but a gymnastics gym and find out if they have any they'll sell you. They're always cirplusing their old ones, cause gymnasts need WAY more impact protection than your average martial artist. I have a mat that I use to practice breakfalls and stuff like that. I got it for like $20 at a gymnastics studio. They were just gonna toss it, because the padding was getting a little tamped down from so many gymnasts landing on it. It suits my purposes just fine, though.