Sale 1:

Sold for Dead Presidents Das Gutenkutteharen (Mini at 20.5 below) + 1 key

No outpost

Seller: http://backpack.tf/profiles/76561198125791160#!/compare/1487894400/1487980800

Buyer: http://backpack.tf/profiles/76561198210073617#!/compare/1487808000/1487980800

The seller of this sale is currently re-selling another one for 22 keys. Going to call 22 the B/O.

X = 22

Sale 2:

Sold for Bubbling Brainiac Hairpiece (18.5)

http://www.tf2outpost.com/trade/28831887 - B/O of 18

Seller: http://backpack.tf/profiles/76561198080179568#!/compare/1489708800/1489795200

Buyer: http://backpack.tf/profiles/76561198070143554#!/compare/1489795200/1489881600

X = 18 (Capped by B/O)

Sale 3:

Sold for Circling Heart Handyman’s Handle (18)

http://www.tf2outpost.com/trade/28812346 - B/O of 17

Seller: http://backpack.tf/profiles/76561198355208726#!/compare/1488499200/1488585600

Buyer: http://backpack.tf/profiles/76561198137326742#!/compare/1488499200/1488585600

X = 17 (Capped by B/O)

Sale 4:

Bulk for something

Seller: http://backpack.tf/profiles/76561198070143554#!/compare/1490140800/1490313600

Buyer: http://backpack.tf/profiles/76561198125791160#!/compare/1490227200/1490313600

Dead Presidents Das Gutenkutteharen Mini:

http://backpack.tf/suggestion/5912cb60c440454ced2befa2

Sellers:

22 keys:

http://i.imgur.com/PSOLVAn.png - 2 months

http://backpack.tf/u/76561198125791160

$48 (~23 keys: – Marketplace.tf

http://www.tf2outpost.com/trade/29134915

http://backpack.tf/item/1677811812

Sales at:

17

18

22

Going with 17-22.