Wellll... Somewhere I missed that it's a 150, and due to density altitude concerns (and fat pilots!) we don't see too many of them used as trainers here.
$70 might be fine if he's not paying a mechanic, since he's doing the work himself.
I'd just watch it when the squawk list starts to get long and stuff isn't getting fixed. I soloed in a similarly set up 150 long long ago, and it eventually had to be sold because it wasn't earning it's keep.
Just before that, various things started getting "deferred maintenance" that really shouldn't have been deferred and my instructor recommended we switch airports and FBOs.
I've also seen the opposite where in a large flight club, the airplanes owned and leased back by the mechanics were the most sound rentals, and the private owner leasebacks were nickel and dimed.