1 year outdated:

Sale 1

http://backpack.tf/profiles/76561198202382535#!/compare/1488326400/1489276800

1:1 for Black Hole Shooter's Topi

GBH Topi mini

Note: Can't find any mini on Topi except that, which looks high.

http://backpack.tf/profiles/76561198209349268#!/compare/1488153600/1488240000

Taking Topi as 40 according to seller:

http://screenshot.sh/n9IAlxGJoAOw1

X = 40

Note: High

Sale 2

http://backpack.tf/profiles/76561198161134716#!/compare/1488844800/1488931200

1:1 for Mega Strike Party Trick (35, in date)

X = 35

Sale 3

http://backpack.tf/profiles/76561198341449455#!/compare/1488844800/1488931200

http://backpack.tf/profiles/76561198166581172#!/compare/1488844800/1488931200

Looks like they traded it and then traded back same day.... Something's fucked up here.

http://backpack.tf/item/2674482062

Sale 4

http://backpack.tf/profiles/76561198039698600#!/compare/1489104000/1489190400

Sold for GE Tin-Gallon (40, in date) + 1.5 key

X = 41.5 key rounding to 42

Note: High

Sale 5

http://backpack.tf/profiles/76561198258531314#!/compare/1489190400/1489276800

Sold with:

- Flames Defiant Spartan (85 keys, 2 weeks unsold @ 85: http://screenshot.sh/oAiVOzwnxBjfh)

- T-w Condor Cap (55 keys, bumped seller @ 55 for 4 days: http://screenshot.sh/ou0Wia5Xzgkg9)

Note: If those link don't work for you, try to copy/paste them in search

- 15 keys

For:

- PE Rotation Sensation (163.5 rounding to 164, in date)

X = 164 - 85 - 55 - 15 = 9

Note: I'm sure it was an overpay but since I can't find BO, taking as low.

Sale 6

http://backpack.tf/profiles/76561198139291293#!/compare/1489449600/1489536000

26 pure

X = 26

Sale 7

http://backpack.tf/profiles/76561198216461152#!/compare/1489536000/1489622400

Keys don't show

Sale 8

http://backpack.tf/profiles/76561198216461152#!/compare/1489968000/1490054400

17 pure

X = 17

Note: Low

Sale 9

http://backpack.tf/profiles/76561198136469690#!/compare/1490227200/1490313600

28.3 rounding to 28 keys

X = 28

Sellers:

http://www.tf2outpost.com/trade/28845353 - 30 keys, almost month unsold

http://screenshot.sh/oeWGyVPfSAv5N - 37 on classies, just added

Summary:

Sales @ 9, 17, 26, 28, 35, 40, 42

9 and 17 are low

40 and 42 are high (because of sellers)

Taking 26-35 range