Sale 1:

Quicksold for 29 keys

http://www.tf2outpost.com/trade/27865259 - B/O of 30, buyer offers on trade

Seller: http://backpack.tf/profiles/76561198177739978/#!/compare/1455955200/1458457200

Buyer: http://backpack.tf/profiles/76561198062857508/#!/compare/1456041600/1456128000

X = 29

Sale 2:

Quicksold for 30 keys

http://www.tf2outpost.com/trade/27998404 - B/O of 35

Seller: http://backpack.tf/profiles/76561198051502238/#!/compare/1458950400/1459036800

Buyer: http://backpack.tf/profiles/76561198044010685/#!/compare/1458950400/1459036800

X = 30

Sale 3:

Quicksold for 31 pure?

http://www.tf2outpost.com/trade/27817639 - B/O of 31

Seller: http://backpack.tf/profiles/76561198069892390/#!/compare/1454745600/1454832000

Buyer: http://backpack.tf/profiles/76561198090104341/#!/compare/1454832000/1455177600

Don’t know if it was actually a pure sale or not, sorting by time doesn’t help either. Doesn’t matter anyways, B/O was 31 and it sold in less than a day.

X = 31

Sale 4:

Quicksold for 32?

http://www.tf2outpost.com/trade/27963204 - B/O of 32

Seller: http://backpack.tf/profiles/76561198046431509/#!/compare/1458111600/1458198000

Buyer: http://backpack.tf/profiles/76561198082745608/#!/compare/1458198000/1458457200

X = 32

Sale 5:

Quicksold for 33 keys

http://www.tf2outpost.com/trade/27999555 - B/O of 33

Seller: http://backpack.tf/profiles/76561198044010685/#!/compare/1459036800/1459123200

Buyer: http://backpack.tf/profiles/76561198120665449/#!/compare/1459036800/1459123200

X = 33

Sale 6:

Sold with a key for Pro. KS Aussie Knife

Seller: http://backpack.tf/profiles/76561198062857508/#!/compare/1456128000/1456214400

Buyer: http://backpack.tf/profiles/76561198025022308/#!/compare/1455955200/1456214400

X + 1 = 35

X = 34

Anything under 34 is too low.

Sale 7:

Sold for 31 keys in ~4 days

No outpost link available

Seller: http://backpack.tf/profiles/76561198157455991/#!/compare/1455955200/1456041600

Buyer: http://backpack.tf/profiles/76561197964171516/#!/compare/1456041600/1456128000

X = 31

Sale 8:

Sold for 35 keys

http://www.tf2outpost.com/trade/27936217 - Deleted B/O

Seller: http://backpack.tf/profiles/76561198146352451/#!/compare/1457938800/1458025200

Buyer: http://backpack.tf/profiles/76561198103825331/#!/compare/1457938800/1458025200

X = 35

Sale 9:

Sold with 5 keys for Galactic Codex Phononaut

http://www.tf2outpost.com/trade/27640435 – B/O of 40, Seller confirms sale (legend)

Seller: http://backpack.tf/profiles/76561198045388088/#!/compare/1454400000/1454486400

Buyer: http://backpack.tf/profiles/76561198069892390/#!/compare/1454400000/1454486400

X + 5 = 43

X = 38

Sale 10:

Sold (with a cheap skin) for Aussie Blackbox + Aussie Knife

http://www.tf2outpost.com/trade/27883556 - B/O of 45, Seller confirms sale (legend)

Seller: http://backpack.tf/profiles/76561198101210182/#!/compare/1456646400/1456732800

Buyer: http://backpack.tf/profiles/76561198060927833/#!/compare/1456646400/1456732800

Screenshot: https://imgur.com/a/xGtDX - Credit to EGC | KeRRR and -GoV- ♥Koala♥S>5Unus

X = 18 + 24

X = 42

Sale 11:

Sold with 2 keys for Scorching Larrikin?

http://www.tf2outpost.com/trade/27754187 - No B/O, buyer offers on trade

Seller: http://backpack.tf/profiles/76561198116821062/#!/compare/1453708800/1453881600

Buyer: http://backpack.tf/profiles/76561198074242936/#!/compare/1453536000/1453881600

X + 2 = 53

X = 51

Sale 12:

Sold for Haunted Ghosts Larrikin Robin

http://www.tf2outpost.com/trade/28049804 - B/O of 32, lowered from 35

Seller: http://backpack.tf/profiles/76561198120665449/#!/compare/1460332800/1460592000

Buyer: http://backpack.tf/profiles/76561197991197437/#!/compare/1460332800/1460592000

X = 25

Sale 13:

Sold for Cloud 9 Smoking Skid Lid + 5 keys in items

http://www.tf2outpost.com/trade/27936362 - Deleted B/O

Seller: http://backpack.tf/profiles/76561197964171516/#!/compare/1457337600/1457424000

Buyer: http://backpack.tf/profiles/76561198178290506/#!/compare/1457424000/1457769600

No other valid sales on the Skid lid, should be used to update it.

Sale 14:

Sold for Peace Sign Mining Light

http://www.tf2outpost.com/trade/27991734 - B/O of 40

Seller: http://backpack.tf/profiles/76561198088183290/#!/compare/1459814400/1459987200

Buyer: http://backpack.tf/profiles/76561198192740165/#!/compare/1459900800/1459987200

Couldn’t get a mini on the Mining Light, sales were mostly bulk sales or untraceable.

Sale 15:

Sold with 4 keys for Darkblaze Handle

Seller: http://backpack.tf/profiles/76561198025022308/#!/compare/1457683200/1457769600

Buyer: http://backpack.tf/profiles/76561198086948995/#!/compare/1457683200/1457769600

Can be used to update the Handle

Sale 16:

Sold for Eerie Orbiting Fire Fro + Green Confetti Officer’s Ushanka

http://www.tf2outpost.com/trade/27909921 - B/O of 42

Seller: http://backpack.tf/profiles/76561198082745608/#!/compare/1458111600/1458198000

Buyer: http://backpack.tf/profiles/76561198272542830/#!/compare/1458111600/1458198000

Ushanka is outdated, should fall into the range though.

Sellers:

35 keys:

http://puu.sh/opMtq/c350084c24.png - 6 days

40 keys:

http://puu.sh/opMDl/87e08c722f.png - 4x (2 days, 4 days, 4 days, 1 month)

http://www.tf2outpost.com/trade/28081820 - 3 days, unbumped

42 keys:

http://www.tf2outpost.com/trade/27909921 - 1 month

Sales at:

25

29

30

31

31

32

33

34

35

38

42

51

Range suggested by Polar:

http://backpack.tf/vote/id/570f8dd383de6b22f14abf0d

Going with 32-42