Sale 1:

Sold for 25 keys

http://www.tf2outpost.com/trade/28290804 - B/O of 25

Seller: http://backpack.tf/profiles/76561197993826799#!/compare/1473033600/1473120000

Buyer: http://backpack.tf/profiles/76561198319424662#!/compare/1473033600/1473120000

X = 25

Sale 2:

Sold for Logo Bicorne (outdated) + 3 keys + ~3 keys in metal/items

http://www.tf2outpost.com/trade/28483151 - B/O of 25

Seller: http://backpack.tf/profiles/76561198144654981#!/compare/1474588800/1474675200

Buyer: http://backpack.tf/profiles/76561198283577557#!/compare/1474675200/1475020800

Should cap at the B/O, Bicorne would have to be less than 19 to change the value of this sale.

X = 25 (Capped by B/O)

Sale 3:

Sold for 21 keys in about 3 days

http://www.tf2outpost.com/trade/28596018 - No B/O

Seller: http://backpack.tf/profiles/76561198092290918#!/compare/1478822400/1478908800

Buyer: http://backpack.tf/profiles/76561197963500354#!/compare/1478822400/1478908800

X = 21

Sale 4:

Sold for 20 keys

http://www.tf2outpost.com/trade/28590876 - Deleted B/O

Seller: http://backpack.tf/profiles/76561198088878793#!/compare/1478563200/1478649600

Buyer: http://backpack.tf/profiles/76561198092290918#!/compare/1478563200/1478649600

X = 20

Sale 5:

Sold for Searing Demoman’s Fro (Outdated) + 2 keys

No outpost

Seller: http://backpack.tf/profiles/76561197964171516#!/compare/1473552000/1473638400

Buyer: http://backpack.tf/profiles/76561198144654981#!/compare/1473552000/1473638400

This should fit in the range. The Fro has sellers at and less than the current price, so I doubt this sale would go over 25

Sellers:

22 keys:

http://i.imgur.com/ztwpBRM.png – lowered 3 days ago

http://www.tf2outpost.com/trade/28606472 - Listed as 22 keys + 15 ref here

http://backpack.tf/u/76561197963500354

24 keys:

http://www.tf2outpost.com/trade/28611196 - 6 days

http://backpack.tf/u/76561198138844587

28 keys:

http://www.tf2outpost.com/trade/28604471

http://backpack.tf/u/76561198058076663

Sales at:

25 (2x)

21

20

Going with 20-25