Parts....really are not an issue. In the last 4 years, they've actually become pretty popular. You can buy a complete motor for under $400 (I bought one for $212.00) for the one buggy that had a blown motor, when I bought it.
I know the ATV's are really popular with getting kids involved with the 110's going new for $800 or less......the dune buggies seem to be really big down south and in the south west as well.
At 40MPH.....the tach reads 7000rpm. And yes, they will blow up if constantly run at that. On the trails, I'd say more like 25MPH running around 3K to 5K is more like it. People say red line is 9000, I'm thinking I'd have parts all over if I ever got the motor that wound up.
Quality is NOT the chinese major concern for sure.....I've got one buggy with a motor that leaves the classic pre 80's Harley oil puddle on the floor. I am sure the gaskets and assembly have alot to be desired. Oh, I know what I got into......and I refuse to pay alot for this stuff......bottom line.....Its fun. Can't get arrested for that, well, maybe if I break the law.
We've run them about 5 hours so far.....and haven't had to mess with them, but I am still mixed on how long they will actually last.