Purchasing a minecon cape?

So I have not been able to attend any of the minecon conventions yet and I’m planing to purchase a Minecraft minecon 2016 cape from a seller online.

By having not having any hands on experience on owning a Minecraft minecon cape if the seller transfers the Minecraft cape onto my account can he then take it back? What I’m asking is, is it linked to his account and can the seller take it back at any time if he wants?

I’m trying not to get scammed so any info will help.