I think if you ask someone for a gift it’s gauche to then immediately resell it. I also think it’s inbounds for someone to say, like at an office, “this is for people to use, not sell. If you don’t like baseball, please allow someone who does to use it”
I guess I see it as different when someone requests a gift, either by asking or signing up for tickets. For an unsolicited gift, I say you’re free to do what you want.
PS. I apologize for the part I played in getting us here from “Bryce Harper trade discussion”