Proof:

Not exact though…

http://www.tf2outpost.com/trade/11044513

sold for a bud

Proof: http://www.tf2outpost.com/trade/11196570

http://www.tf2outpost.com/trade/10549077

sold for s f sniper rifle + parts. A 25 keys approximately (see backpack)

http://www.tf2outpost.com/trade/9755864

c/o of a bud. A week ago.

http://www.tf2outpost.com/trade/11865582

b/o of 24 keys

http://www.tf2outpost.com/trade/9152693

sold for a bud

Proof: http://www.tf2outpost.com/trade/11681671 see item history

http://www.tf2outpost.com/trade/11857566 sold for bubbling salty dog (20 keys with overpay) + 6 ref (1.1 keys) 3 tod tickets (1.3 keys) and an australium gold mecahmedes (0.8keys) which is (23 keys)

http://i.imgur.com/G8ukFDf.png

sold for festive fj (0.2 keys) and festive ambassador (0.4 keys) and festive ubersaw (0.2 keys) festive gl (0.6 keys) and festive minigun (2 keys) and festive rocket launcher (2.7 keys) and festive sniper rifle (1.5 keys) and festive wrench (1.3 keys) and festive scattergun (2.9 keys) and EA (4 keys) and festive medigun (2 keys) festive knife (1.9keys) and double cross com (3.8 keys) and festive flamethrower (1.4 keys) which is 24.4 in items. Used a calculator

Conclusion:

SInce many trades have been completed for 1 bud, I think the best price for this is that. 23 for the lower end (mecha medes trade + tod tickets) and 25 for the strange festive sniper rifle trade.