Sale 1:

Sold for $85 on Marketplace.tf

https://marketplace.tf/items/30375;5;u110

https://backpack.tf/item/5229263580

85/1.9 = ~44.7

X = 45

Sale 2:

Sold for Dead Presidents Killer Exclusive (30)

http://www.tf2outpost.com/trade/29280491 - No B/O

Seller: https://backpack.tf/profiles/76561198090956917#!/compare/1505001600/1505433600

Buyer: https://backpack.tf/profiles/76561198096846337#!/compare/1505174400/1505606400

X = 30

Sale 3:

Sold for 29 keys in ~3 days

No outpost

Seller: https://backpack.tf/profiles/76561198197287330#!/compare/1508976000/1509062400

Buyer: https://backpack.tf/profiles/76561198124789927#!/compare/1508976000/1509148800

X = 29

Sale 4:

Sold with several keys worth of items for Slumber HWNN

Seller: https://backpack.tf/profiles/76561198265806460#!/compare/1506038400/1506124800

Buyer: https://backpack.tf/profiles/76561198148097538#!/compare/1505520000/1506211200

Should be used on the HWNN.

Sellers:

44 keys:

https://i.imgur.com/XsBllHd.png - 3 months

Sales at:

29

30

45

29 sold in a pretty short amount of time. Excluding 29.

3-month old seller at 44 shows that it does not sell well for 44 or over. Excluding 45.

Going with 30 flat.