Hey, I have a proper foam roller. But when i started i just went to CLARK Rubber and got a piece of foam cut $10.
PS: The best thing i have found now, is the CLARK rubber foam has two parts, the outer part is soft foam and the inner "CORE" is harder. After continuous use they seperate, now the good part.
By some 4-5" PVC drain pipe and you slip the outer soft foam over the pipe.
It makes the best roller, hard but soft if you know what I mean.
I'll post a PIC up tomorrow.
PS: It will last a lifetime and will not "FAIL" as the all foam ones do after reasonable use.
The more expensive ie: $60+ have a hard PVC liner to stop this.