Considering that this guy tried to rip you off already, I wouldn't offer him ANYTHING. Just walk away- from his "custom made"(hahahahahahahaha) guitar, and especially from HIM. You're looking to this guy to teach you, and he betrayed your trust.
I had a similar Ibanez that had that exact same "custom made" logo. I picked it up off the wall at Gc, and they had about a DOZEN of them. I paid about $500 for mine NEW. I wouldn't trust your teacher for the correct time of day.