Hi James,
I just got a quote from this company for a replacement belt:
GreenBelt
The belt that I need replaced is just over 6' long, 20" wide. The quote was just under $200.00, which is not cheap, but better than I thought it would be.
Something else I learned, which may be helpful to you is this: You can repair your existing belt with some pieces from and old belt. Stitch the patches to your existing belt where you've got holes or tears with "Nomex" thread. Nomex is heat resistant, very important! Some of the companies who make the belts will also sell you a repair kit that includes these items for you to do your own repair work.
Good luck!
Sue