I bought one of these buggies last year after nearly 10 years of not running anything at all. With a 10.5 in it, I beat the living snot out of it learning how to drive/race on dirt again, and didn't break a darn thing.
They're tougher than they seem, even with lawn darts and sumer saults down the back stretch. The standard parts are WAY more forgiving of incidents than the carbon parts.
That said, I ALWAYS keep a spare set of Avid bearings, front and rear A arms, C hubs, steering knuckles, suspension hardware, and spur gears. So far, due to a particullarly hard nose in lawn dart, I've only had to replace a spur due to a shifting motor and a gear cover due to a loose pinion (melted all the way through!).