A kawi mechanic. Should be well maintained, I would think. If the bike is super clean, No dirt in the nooks and crannies, clean airbox, fresh plastic, starts and runs smooth, that sorta bike, I'd feel pretty good about it.
I know its way basic, but if it doesn't run, or looks like it was on the trails 5 minutes ago with wore-out tires, filthy air filter, nasty plastic and graphics, leaking forks or shock, I start really picking it apart. I would be looking for a bike that has had all of the basic maintenance kept up. A leaky seal, by itself is no big deal, but if all of them leak, then whats the chances anything has been done? Grab wheels, twist on them and try to find wheel bearring play, lift and lower swing arm to check for bearring wear. Sprockets having straight teeth, rear fender mounted straight ( sub-frame condition), push down as far as possible on seat and let it return. If its just spring, adjust it to slow it down, to be sure its not blown. Like I said, one thing is no big deal, all things can be expensive. I like to call the bluff of a guy saying it was recently rebuilt. I just ask to see receipts. That either solidifies the sale or can bring the price down, if it was a bluff. The real truth is, it'd be a miracle if you can just go ride it with no repairs, but avoid a basket case.
Don't forget to get info on what oils the owner has been using, along with the ratio, fuel octane, jetting settings and hit the guy up for any extra parts in boxes, that he may never need again. Don't want her to get home sick..........Good Luck