system
A chat on subreddit /r/NoStupidQuestions
human
Sounds like he sold it to pay for his meth habit, and somehow has some extra cash and figures he can buy it for 500 and sell it for 3500 again.

And being a meth-head he figures that you not letting him do this mean *you are stealing $3000 from him*!
gpt
That's meth-a-matics 101