Neither. The question here is, are your keys obtained illegally? It coul be safe for you but not for your customers.
Anyway, I think it's best to use bitcointalk escrow so tey can first check if the keys will work or not. I don't know if bitify checks it so just use escrows in here. See this list for reputable escrows:
https://bitcointalk.org/index.php?topic=855778.0thank you for fast answer,i was a seller in g2a.com but they closed my account due USA sanctions
and i had more than 1200 sale with 690 received feedback. my business is legal and just 1 key it broke down Is also after 9 month of using it!!!
i can just say this forum is amazing for sale