What's the gunpowder value/ diamond?
I think iDogeTwinkies estimate is pretty good in the economy of the server in the last version. I expect you could get even more now since Shulker Chests should be in high demand as everyone’s Ender Chests fill up. (And GP helps to speed up travel in the End) Plus I doubt there are many GP farms as of yet. I’d probably start at 2 GP per diamond or a stack for 4DB and adjust as necessary.