5 exists. None on the market. Found one hat with retracable sales. Original prices were used and overpay was calculated.

History of said hat: http://backpack.tf/item/1664178039

Sold for a DBD Strontium Stove Pipe ([url]http://backpack.tf/item/2454598369[/url]) - 1.4*0.9 = 1.3

Backpacks before:

• [url]http://backpack.tf/profiles/76561198059677141?time=1398841200[/url]
• [url]http://backpack.tf/profiles/76561198065042183?time=1398668400[/url]

Backpacks after:

• [url]http://backpack.tf/profiles/76561198059677141?time=1398927600[/url]
• [url]http://backpack.tf/profiles/76561198065042183?time=1399012787[/url][li]

Sold for 22 keys - 1.2

Backpacks before:

[li][url]http://backpack.tf/profiles/76561198059677141?time=1398668400[/url]
• [url]http://backpack.tf/profiles/76561198126003176?time=1398668400[/url]

Backpacks after:

• [url]http://backpack.tf/profiles/76561198059677141?time=1398754800[/url]
• [url]http://backpack.tf/profiles/76561198126003176?time=1398754800[/url], looks like he immediately got another unusual with the keys and his stuff.

Hat + 4 keys sold for a Strange Blizzardy Private Eye ([url]http://backpack.tf/item/1000878152[/url]) - 1.4*0.9 - 0.2= 1.1 (strange quality barely adds to the value)

Backpacks before:

• [url]http://backpack.tf/profiles/76561198126003176?time=1398582000[/url]
• [url]http://backpack.tf/profiles/76561198066312808?time=1398582000[/url]

Backpacks after:

• [url]http://backpack.tf/profiles/76561198126003176?time=1398668400[/url]

[li][url]http://backpack.tf/profiles/76561198066312808?time=1398668400[/url][li]

Other sales of this hat are either invalid or not retracable. These proofs and sales were taken into consideration when calculating the range. Any feedback, proofs, counter-proofs, better range suggestion are appreciated and I will act and respond accordingly.