It’s against Paypal policy. Paypal tracks website activity, and has suspended my account on two occasions for fielding “raffle” entries via paypal for people injured or wronged in the gun community.
I would say our policy on gifting would be the least of your worries in using the gifting practice. As a seller you could lose the access to the funds. As a buyer you are completely unprotected when you gift.
Rule? Not really. I view it as identifying a scammer, and have told people how I view the practice.