This took so long it's not even funny.

Sold for a Steaming Vintage Tyrolean(18 Keys with Overpay)

http://backpack.tf/profiles/76561198067579392?time=1435906800

http://backpack.tf/profiles/76561198067579392?time=1435993200

Sold for 19 Keys

http://backpack.tf/profiles/76561198059021831?time=1437375600

http://backpack.tf/profiles/76561198059021831?time=1437462000

http://backpack.tf/profiles/76561198177154519?time=1437462000

http://backpack.tf/profiles/76561198177154519?time=1437548400

Sold for a Miami Nights Firewall Helmet(12 Keys with Overpay) and ~3 Keys in Sweets(15 Keys total)

http://backpack.tf/profiles/76561198072098497?time=1441782000

http://backpack.tf/profiles/76561198072098497?time=1441954800

Sold for a Vivid Plasma Scotch Bonnet(17 Keys with Overpay)

http://backpack.tf/profiles/76561198055733271?time=1437894000

http://backpack.tf/profiles/76561198055733271?time=1440054000

Sold for a Dead Presidents Geisha Boy(14 Keys with Overpay)

http://backpack.tf/profiles/76561198141865466?time=1440054000

http://backpack.tf/profiles/76561198141865466?time=1440140400

Sold for a Bubbling Le Party Phantom(18 Keys with Overpay)

http://backpack.tf/profiles/76561198141865466?time=1439794800

http://backpack.tf/profiles/76561198141865466?time=1440054000

Sold for 15 Keys

http://backpack.tf/profiles/76561198152529163?time=1441004400

http://backpack.tf/profiles/76561198152529163?time=1441177200

Sold for a Strange Festive Rocket Launcher(14 Keys with Overpay)

http://backpack.tf/profiles/76561198067741687?time=1442818800

http://backpack.tf/profiles/76561198067741687?time=1442905200

Sold for a Strange Festive Spec KS Rocket Launcher(15 Keys with Overpay)

http://backpack.tf/profiles/76561198141221579?time=1440918000

http://backpack.tf/profiles/76561198141221579?time=1441004400

Sold for a Smoking Samur-Eye(13 Keys with Overpay) and 3 Keys(16 Keys total)

http://backpack.tf/profiles/76561197972854064?time=1441004400

http://backpack.tf/profiles/76561197972854064?time=1441090800

Sales seem to fit, 14-19 Keys should be fine.

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