I don't even know.

Sold for a Nuts & Bolts Glengarry Bonnet(10.5 Keys, rounding to 11)

http://backpack.tf/profiles/76561198209158951/#!/compare/1458284400/1458370800

Sold for a Purple Confetti Birdcage(15.5 Keys) and ~1.5 Keys in Sweets(17 Keys total, Outlier)

http://backpack.tf/profiles/76561198076020691/#!/compare/1453622400/1453708800

Sold for 11 Keys

http://backpack.tf/profiles/76561198129698369/#!/compare/1455868800/1455955200

Made 17 Keys an outlier due to a 15 month unsold on classifieds, and the sales at less. 11 Keys should be fine.

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