The disc repair machines for consumers are crap. I've got a local video game store that has a $2000 disc repair machine. It costs $4 to repair each disc. I think the best way to do it is order polishing pads for the expensive commercial repair machines, use an orbital power sander and glue some polishing pads to it. the machine shoots water at the discs, but if you are using power tools you may get electrocuted.
