One of these actually sold.

Proof:

Solds:

http://backpack.tf/profiles/76561197972681076?time=1430754483 (compared with the day before sold a holy grail battin a thousand taunt. The buckaroos guy added a pro ks collectors black box tho)

Mini on the battin:

http://backpack.tf/profiles/76561198063640894?time=1429316462 (compared to the day after he sold it for 30 keys + strange festive sandvich ~ 4 keys + Australium spec ks frontier justice ~ 11) So thats 46 keys. No overpay needed because he payed mostly in pure.

Mini on the black box:

There is a seller for 28 keys but there is 1 seller for a kit http://www.tf2outpost.com/trade/26018245 (15 keys) + 4 is 19. But normally it goes down ~2-3 keys if applied to an item. So thats about 16 keys.

So thats 46 - 16 = 30 keys left for the buckaroos. Makes sense tho since its near scorching/cloudy moon