And behind door #1 we have
How can anyone sell a bike in this condition. I would have beat that guy down to 3K
So the seller used the photos from his purchase, at what point do you have to tell your neighbor to just sell it for whatever he can get, and then take up knitting... if he couldn't tell the bike was beat to shit, he might not have the common sense t be allowed to even freaking ride.
Otherwise you just setting yourself up to be his free repair shop.
Most of us never went to "mechanic" school, we just hadda fix something we just broke, so we figured out how.
We all started out no knowing shit, made mistakes, busted knuckles, tore something down, rebuilt it, only to realize we just fucked it all up, then hadda rip it apart again because we forgot a stinking wrist pin clip. c e, or some other stinking foul ass letter clip that let some damned piston seize, or ring gear to slap, or master link to come apart, or forgot to put a oil filter in after a rebuild and shit oil all over the motor and mamma's garage.
But then after a few decades, lots of conversations, and thousands of hours spent wrenching and riding, we get to a point where we go "hmmm,, do I want to put a rekluse in this one or go back to the one finger hydraulic",
and that is how we became real live dirt bikers.
Your a good guy bro, don't let yourself get pigeonholed, been there, and it sucks when you realize you just suckered yourself.
Ask yourself, does he work on his own car, or even show an interest in getting his hands dirty working on it with ya?