Sale 1:

Sold for Pro. KS Aussie Stickybomb Launcher (20) + Circling TF Logo Samur-Eye (mini at 21.5 below)

No outpost

Seller: http://backpack.tf/profiles/76561198041902665#!/compare/1475712000/1475884800

Buyer: http://backpack.tf/profiles/76561198044519477#!/compare/1475798400/1475884800

X = 42

Sale 2:

Sold for Stormy Whirly Warrior (37) + ~3 keys in painted items

http://www.tf2outpost.com/trade/28466591 - No visible B/O

Seller: http://backpack.tf/profiles/76561198112612121#!/compare/1473379200/1473465600

Buyer: http://backpack.tf/profiles/76561198054976998#!/compare/1473379200/1473465600

Whirly Warrior is in-date at 44.5, however, there is a 22 day old seller at 37. Therefore, going with 37 for the stormy warrior.

X = 40

Sale 3:

Sold for Strange Killstreak Batsaber (38)

No outpost

Seller: http://backpack.tf/profiles/76561198069527288#!/compare/1476835200/1476921600

Buyer: http://backpack.tf/profiles/76561198049834485#!/compare/1476748800/1476835200

X = 38

Sale 4:

Sold for Killstreak Australium Scattergun (28) + White Vintage Bill’s (9.25)

Seller: http://backpack.tf/profiles/76561198081963512#!/compare/1473638400/1473724800

Buyer: http://backpack.tf/profiles/76561198058899586#!/compare/1473638400/1473724800

X = 37

Sale 5:

Sold for 33 keys

http://www.tf2outpost.com/trade/28511914 - B/O of 38

Seller: http://backpack.tf/profiles/76561198058899586#!/compare/1475366400/1475625600

Buyer: http://backpack.tf/profiles/76561198309279405#!/compare/1475539200/1475625600

X = 33

Sale 6:

Sold for 33 keys

http://www.tf2outpost.com/trade/28482211 - B/O of 38, seller confirms sale (Legend)

Seller: http://backpack.tf/profiles/76561198160909941#!/compare/1474070400/1474416000

Buyer: http://backpack.tf/profiles/76561198071371521#!/compare/1474329600/1474416000

X = 33

Sale 7:

Sold with 2 keys for Logo Tricorne (Mini at 15 below) + Cloud 9 Stout Shako (Mini at 20 below)

No outpost

Seller: http://backpack.tf/profiles/76561198046921199#!/compare/1476748800/1476835200

Buyer: http://backpack.tf/profiles/76561198069527288#!/compare/1476748800/1476835200

X = 33

Sale 8:

Sold with Pool Party (2) for Minimal Wear Aqua Marine Rocket Launcher

Seller: http://backpack.tf/profiles/76561198054976998#!/compare/1473465600/1473552000

Buyer: http://backpack.tf/profiles/76561198160909941#!/compare/1473465600/1473552000

Rocket Launcher is outdated, can be used to update it instead.

Sale 9:

Sold with 5 keys + ~1 key in items for Circling Heart Flipped Trilby

http://www.tf2outpost.com/trade/28523305 - B/O of 40

Seller: http://backpack.tf/profiles/76561198309279405#!/compare/1475625600/1475712000

Buyer: http://backpack.tf/profiles/76561198041902665#!/compare/1475625600/1475712000

Would be better to update the Trilby with this sale

Logo Samur-Eye Mini:

http://backpack.tf/suggestion/5811c1ffc44045583b3b9c22

Cloud 9 Stout Shako Mini:

Sold for 20 keys

No outpost

Seller: http://backpack.tf/profiles/76561198153794814#!/compare/1472860800/1472947200

Buyer: http://backpack.tf/profiles/76561198233389656#!/compare/1472860800/1472947200

X = 20

Logo Tricorne Mini:

http://backpack.tf/suggestion/5811cdb0c4404502314a6135

Sellers:

40 keys:

http://www.tf2outpost.com/trade/28499386 - 1 month

http://i.imgur.com/aVO6oGu.png

http://backpack.tf/u/76561198117597416

http://www.tf2outpost.com/trade/28565469

http://i.imgur.com/5GSjveT.png

http://backpack.tf/u/76561198049834485

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

http://backpack.tf/u/76561198090956917

41 keys:

http://www.tf2outpost.com/trade/28560944

http://i.imgur.com/2KsSQBN.png - listed for 42 here

http://backpack.tf/u/76561198071371521

42 keys:

http://www.tf2outpost.com/trade/28543403

http://backpack.tf/u/76561198048792033

Sales at:

33 (3x)

37

38

40

42

42 may be a bit too high, due to the abundance of sellers at less than 42, one of them going 2 months old, another going a month old.

Going with 33-40.