I'd try buying this if kush didn't have it.

Sold for 1 Bud + 10 Keys(1.7 at the time of sale)

http://backpack.tf/profiles/76561198062056544?time=1420316473 -> http://backpack.tf/profiles/76561198062056544?time=1420444800

http://www.tf2outpost.com/trade/24299245

Sold for a Cloud 9 Cold Killer(2.9 with Overpay, can't use because it was used for the cold killer's update)

http://backpack.tf/profiles/76561198054762173?time=1420512811 -> http://backpack.tf/profiles/76561198054762173?time=1420617600

Sold with a Collector's Spec KS Air Strike(~0.6 with Overpay) for a Bubbling Vive Le France(3 with Overpay)(2.4 Total)

http://www.tf2outpost.com/trade/24520947

http://backpack.tf/item/2877419409 Air Strike History

Collector's Spec KS Air Strike mini suggestion

Sold for a Genuine Grandmaster(~8 Keys with Overpay at the time of the sale)

http://backpack.tf/profiles/76561198045791914?time=1419494400 -> http://backpack.tf/profiles/76561198045791914?time=1419620758

Going with 8 Keys

Two sales, 1.7-2.4 should be fine.

Additional Proof/Counter-Proof/Constructive Criticism/Feedback is always appreciated.