That's also the stuffty website being scum and cranking up the price of its limited stock
I think it's Badspots decision actually.
Plimus sneakily bumped up their commission by an extreme amount for sellers who were earning less than $2,500 (like Badspot).
It meant that eventually Badspot was recieving no money for every key they sold.
So, he bumped the prices up to crazy high, so that it deters people from buying from them, and Plimus aren't rewarded for their cheap tricks. At the same time, should someone decide that a 2k key is worth £400, then Badspot should still make some money off of that sale.
They only have a limited number of keys to sell, and Badspot isn't losing out on sales by making the prices high, since he is still regularly selling through blockland.us, Amazon and Steam.