Teac used to make a rubber conditioner that came in a bottle for reconditioning rubber pinch rollers and guides and it worked great on belts. I actually still have a bottle of this, but I'm sure on the Pro audio use side, someone must make the same thing? Maybe Numark or Tascam.
Try this URL for belts cheap:
http://www.turntablebasics.com/belts
Try this URL for belts cheap:
http://www.turntablebasics.com/belts