Ok, I've found other users on Reddit experiencing the same.
100% scam.

I think I'm gonna troll him a bit from now on lol.

Thanks for the quick answers everyone!

Hello everyone,

first post here, I need some advice because I'm selling an app and the buyer wants to pay in BTC.
What he asked is to register a BTC wallet on crypto247exchange so he can send me the money via Escrow, because apparently he reached his withdrawal monthly limit, and can only send unlimited BTC to wallets registered on the website. Just to be sure, I'm gonna send him the source code of the app only after receiving the payment.

What I'm asking is:

1) Is this method safe and the site reliable?
2) Can this be part of a scam and if yes, how?
3) After receiving the money, will it be hard to convert my money to fiat on my bank account?
4) What are the withdrawal limits and exchange fees?

I know it's a lot to answer to, so thanks in advance.