Sale 1:

Sold for Max’s (19) + B.M.O.C (4) + 2 keys

http://www.tf2outpost.com/trade/28798012 - B/O of 24

Seller: http://backpack.tf/profiles/76561198021055079#!/compare/1488585600/1488672000

Buyer: http://backpack.tf/profiles/76561198111535925#!/compare/1488585600/1488672000

http://imgur.com/a/RhvRB

X = 24 (Capped by B/O)

Sale 2:

Sold for 20 keys

http://www.tf2outpost.com/trade/28674629 - No visible B/O

Seller: http://backpack.tf/profiles/76561198076020691#!/compare/1484006400/1484092800

Buyer: http://backpack.tf/profiles/76561198198563466#!/compare/1482624000/1484784000

X = 20

Sale 3:

Sold with a key for Aussie Knife (18) in ~3 days

http://www.tf2outpost.com/trade/28733900 - Deleted B/O

Seller: http://backpack.tf/profiles/76561198002757046#!/compare/1485043200/1485129600

Buyer: http://backpack.tf/profiles/76561198296967233#!/compare/1485129600/1486080000

X = 17

Sale 4:

Quicksold to Rubi for 16 keys

Seller: http://backpack.tf/profiles/76561198090618622#!/compare/1484784000/1484956800

Buyer: http://backpack.tf/profiles/76561198002757046#!/compare/1484870400/1484956800

X = 16

Sale 5:

Sold for 15 keys in ~4-5 days

http://www.tf2outpost.com/trade/28721623 - B/O of 18

Seller: http://backpack.tf/profiles/76561198045977760#!/compare/1484870400/1484956800

Buyer: http://backpack.tf/profiles/76561198090618622#!/compare/1484784000/1484956800

X = 15

Sale 6:

Sold with <3.5 keys in items for Searing Backbiter’s Billycock

Seller: http://backpack.tf/profiles/76561198296967233#!/compare/1486080000/1486512000

Buyer: http://backpack.tf/profiles/76561198021055079#!/compare/1485993600/1486080000

http://imgur.com/a/F2W3M

Probably better to update the Backbiter’s with this sale.

Sale 7: (Strange)

Bulk for Terror-Watt Hong Kong Cone

Seller: http://backpack.tf/profiles/76561198105741918#!/compare/1486339200/1488758400

Buyer: http://backpack.tf/profiles/76561198090956917#!/compare/1486252800/1486339200

Sellers:

25 keys:

http://i.imgur.com/FJJYsbI.png – 29 days

http://backpack.tf/u/76561198086948995

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

http://backpack.tf/u/76561198090956917

http://www.tf2outpost.com/trade/28771225 – 3 weeks

http://backpack.tf/u/76561198032029065

Sales at:

15

16

17

20

24

Sales at 17 and lower sold pretty quickly. Excluding 17 and below.

Going with 20-24.