First I would see what is wrong with the current saw. if it is just the bands on the wheels, they can be replace for about $25.00 or so.
http://www.searspartsdirect.com/part...FQeRfgodJG8Glg
I would rebuild the old saw. I have one and just spent a little money on it. She works great again. New drive belt, machined pulley's, wheel belts, runs like new.
Buzz.