Sale 1:

Sold for ~11 keys in taunts/items

No outpost

Seller: http://backpack.tf/profiles/76561198354766938#!/compare/1493164800/1493251200

Buyer: http://backpack.tf/profiles/76561198033661509#!/compare/1493164800/1493251200

X = 11

Sale 2:

Sold for Aces High Bolted Birdcage (Mini at 10 below) + 1 key

No outpost

Seller: http://backpack.tf/profiles/76561198235987404#!/compare/1492905600/1493337600

Buyer: http://backpack.tf/profiles/76561198184946878#!/compare/1493251200/1493337600

X = 11

Sale 3:

Quicksold for 10 keys

http://www.tf2outpost.com/trade/28839363 - B/O of 11

Seller: http://backpack.tf/profiles/76561198076339690#!/compare/1489276800/1489881600

Buyer: http://backpack.tf/profiles/76561198090464845#!/compare/1489795200/1489881600

X = 10

Sale 4:

Sold for 10 keys

No outpost

Seller: http://backpack.tf/profiles/76561198090464845#!/compare/1492905600/1493164800

Buyer: http://backpack.tf/profiles/76561198185007761#!/compare/1493078400/1493164800

X = 10

Sale 5:

Sold for 10 keys in 2+ weeks

No outpost

Seller: http://backpack.tf/profiles/76561198344933095#!/compare/1494806400/1494892800

Buyer: http://backpack.tf/profiles/76561198314512963#!/compare/1494720000/1494892800

X = 10

Sale 6:

Sold for Smoking Dead Cone (10) (Buyer’s backpack)

No outpost

Seller: http://backpack.tf/profiles/76561198314512963#!/compare/1495324800/1495411200

Buyer: http://backpack.tf/profiles/76561198244962432#!/compare/1495324800/1495411200

X = 10

Sale 7:

Quicksold for 9 keys + 2 ref

No outpost

Seller: http://backpack.tf/profiles/76561198253339587#!/compare/1495497600/1495584000

Buyer: http://backpack.tf/profiles/76561198306115686#!/compare/1495497600/1495584000

X = 9

Sale 8:

Quicksold for 9 keys

No outpost

Seller: http://backpack.tf/profiles/76561198111365589#!/compare/1494720000/1494979200

Buyer: http://backpack.tf/profiles/76561198025083656#!/compare/1494633600/1494720000

X = 9

Sale 9:

Sold with >0.5 keys in metal for Terror-Watt Plumber’s Pipe

Seller: http://backpack.tf/profiles/76561198207370923#!/compare/1493251200/1493337600

Buyer: http://backpack.tf/profiles/76561198235987404#!/compare/1492905600/1493337600

Was used on the Pipe. Can’t be used here.

Sale 10:

Sold with Spec. KS C.A.P.P.E.R for Terror-Watt Tippler’s Tricorne

Seller: http://backpack.tf/profiles/76561198184946878#!/compare/1493251200/1493337600

Buyer: http://backpack.tf/profiles/76561198095862827#!/compare/1493251200/1493337600

Should be used on the Tricorne.

Aces Birdcage Mini:

http://backpack.tf/suggestion/5940baf9c4404531624c1c33

Sellers:

12 keys:

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

http://backpack.tf/u/76561198033661509

http://www.tf2outpost.com/trade/29201463

http://i.imgur.com/bDGhuH4.png - 3 months

http://backpack.tf/u/76561198066195760

15 keys:

http://i.imgur.com/InWNygA.png - 4 months

http://backpack.tf/u/76561198086948995

Offers:

http://www.tf2outpost.com/trade/29206411

http://backpack.tf/u/76561198055994779

Sales at:

9 (2x)

10 (4x)

11 (2x)

Buyer at 9+:

http://i.imgur.com/GGo7S08.png

Excluding 9

Going with 10-11.