I wonder if a GPL that said you cannot redistribute this for a price equal to or less than the amount you paid for it.
So if you got it free, it is fair to redistribute free or charge for it or whatever. But if the original author sold it to you for $40, you must sell it for at least $41. There's no royalties; all that money is yours, it just means you can't compete with the original author on price alone.
idk tho i gotta think about it