He has no entitlement to anything, period. Unless your a really nice guy then he is entitled to get his deposit back. But most of the time when you buy something the deposit is non refundable unless agreed upon prior.
You could be a douche and not give him a penny back and have to deal with his threats and BS.
Or you could give him his money back and never have to hear from him again.
I had someone try to run a scam on me like this, he gave me $500 deposit for a supercharger then never showed up to pick it up. Then like 6 months later a guy calls me and tells me he was the guys friend and needed to pick up the $500 to post bail for him. I told him there was no way I was giving someones "friend" $500. He could come and get it from me when he got out of jail. I never heard from him again.