I have only had belts wear. I went though a diff pully after eating a rock, but the rear belt was ok. The Front belt ( long one on the HPI cars ) i went though about 2 of those. and I'm still using the original side belt. Still havent damaged that one at all.
Generally i don't think belts are that big of a pain. If you keep the correct tension on them, i dont see why they won't last at least a season.