I purchased lately a domain name through an auction. I am not into the niche of this domain but I thought it is interesting since it is dmoz/yahoo/joeant listed and has many other quality links. I just received a call from the owner saying that they failed to renew the domain because their registrar went out of business. I am confused now, this is his domain name since 2001 and he is really involved in that niche. Should I sell it to him at the same price I bought it? I had the domain through an auction so I am not the one who "stole" the domain from him what should I do?
It's honestly up to you at this point. Get good "Karma" for giving it back plus covering your charges... Or Telling him that fair is fair, and he had just as much of a chance to buy it as you did. You own it now, and it is yours. It would be as if this guy's car was reposessed for not paying, you buying it at auction, and him now bugging you to buy it back. Sure it's not exactly the same, but you get the idea. Tough call. If you really like the name, I say keep it. But that's me.
If he can prove he was the owner and it was registered at Registerfly then I'd be a nice guy and sell it back at the price you paid - maybe with a small profit. If it wasn't RegisterFly and he just forgot to renew then tough noogies - I'd keep it or sell it back at a bigger profit.
And me, too. It's up to you, mhamdi, to decide what's more important for you. If the other party decides to make things ugly, be sure to keep every communication you received from them.