Aerox mileage before full rebuild?

Hiya folks not been on here in a long time. Had a Honda vision last time I posted here. Still have the tzr50 which I love, and had another couple of 50s along the way.

I quite fancy an Aerox for a 70cc kit.
I’ve seen a good condition one with 15k miles which hasn’t had a bottom end rebuild.
How long do these engines last before bottom end goes ?

cheers