PLUS, though Im 99% sure I am wrong, this could be seen as advertising for paypal if you display their logo, but the only map that has been taken down for that was Squad TD and that was because it was a Rival games logo i believe. So i wouldnt worrie about that, but I would keep that tiny detail in mind. But personally I doubt theirs any risk, just dont add the actual logo and that 1% goes to 0%
Paypal rules 70% of the online "marketing money storage market". [Maybe even more] Idk if they're gonna care if they're really going to care if there's one little button in one little awesome custom map that has their name on it. Especially if it means their customers are going to be depositing more money.