I was trying to search for the answer, but I honestly suck at figuring out the search on this site. :c Sorry, as I'm sure this has been answered a million times.
I know (I think) you can only display one of each. But can you buy and then regift/sell extras of each? I think I've been missing out by only buying my one of each birthstone that I can display. :/
I believe you can only have one in your inventory, whether it's displayed or not. If you decide to gift the one you have, you can buy another one at that point so long as you don't already have a duplicate.
Oh ok, that's pretty much what I thought. But then I started seeing collectors selling them, and figured they must be selling extras they have, since they'd prob want to keep 1 for their collection.