There are several sources for the belts and not too expensive. Even some rubber replacements which are cheap.
Not hard to replace if you get the belt that you connect the ends. Times the same as most old Singers.

Ahh, I think I need to correct Quilterman (sorry) We aren't talking about the motor to crank belt. This model has a cleated timing belt that goes from the crank to the underbed bits. Not so easy to find.