Without knowing if his was for a business, or a service mark or trademark, or even some just-well-known name, AND without knowing your location, it’s hard to say more. In the US you could (IaNaL) pursue small claims court, at the cheapest, and try to make an argument that they registered it in bad faith; if they fail to show up I’d guess an order from the court to transfer the domain back to you in exchange for compensating the purchaser for a year of registration would be your best possible (but who-knows how likely; courts are fickle things) outcome.
Outside the US, your local laws might be nicer to you legally.
Thanks, I'm in the US. The site was used as my attempt to learn web dev. I didn't think I had any options, but now it looks like it might be worth looking into further.
Without knowing if his was for a business, or a service mark or trademark, or even some just-well-known name, AND without knowing your location, it’s hard to say more. In the US you could (IaNaL) pursue small claims court, at the cheapest, and try to make an argument that they registered it in bad faith; if they fail to show up I’d guess an order from the court to transfer the domain back to you in exchange for compensating the purchaser for a year of registration would be your best possible (but who-knows how likely; courts are fickle things) outcome.
Outside the US, your local laws might be nicer to you legally.