I remember those did something but no idea what...

Can't find any in the user shops so looking for a PC on

It's a rare collectors item. I'd either throw it in your shop or trades and just stay competative with the price. And if someone offers you a decent amount for it, consider taking it.

It's kinda a weird collection because so much of it is very rare and hard to find, but they are all (to my knowledge) still being released through the tiles game. So people that are trying to complete the collection are oftentimes playing the game to get them.

Someone who only needs a few tiles left to complete a collection might value it at 250mil+, while someone who is just starting to collect them probably wouldn't pay more than 5-10mil for it.