7 month old price!

Sale 1:

Sold for 74 USD (74/1.85) = 40 keys

http://www.tf2outpost.com/trade/27573298

http://i.imgur.com/pVn0ad7.png

Sale 2: (credits to -».•´Woifilicious`•.«-)

Sold with sweets for Orbiting Fire Bonk Boy + 4 keys + sweets = ~34.4 (rounding to 34 keys)

http://www.tf2outpost.com/trade/27191088

http://backpack.tf/profiles/76561198019864333?time=1444374000 (October 9th)

http://backpack.tf/profiles/76561198019864333?time=1444546800 (October 11th)

http://backpack.tf/profiles/76561198019864333?time=1444374000&compare=1444546800

Sale 3:

Unable to identify sale

[no outpost trade]

http://backpack.tf/profiles/76561197972676539?time=1447315200 (November 12th)

http://backpack.tf/profiles/76561197972676539?time=1447488000 (November 14th)

http://backpack.tf/profiles/76561197972676539?time=1447315200&compare=1447488000

Sale 4:

Involved in a bulk deal

http://backpack.tf/profiles/76561198093234248?time=1449216000 (December 4th)

http://backpack.tf/profiles/76561198093234248?time=1449302400 (December 5th)

http://backpack.tf/profiles/76561198093234248?time=1449216000&compare=1449302400

Notes:

None other on the market, this is the only recent identifiable sale.

http://www.tf2outpost.com/trade/27191088 - B/O of 36 keys

Conclusion:

Two valid sales at 34 and 40 keys. Taking a final range of 34-40 keys.

Feel free to support/counter my suggestion!