(counter to http://backpack.tf/vote/id/54b37a8eb88d88d9128b4805)

Sale 1:

Sold for Stormy Storm Dread Knot* ([9.5/13]*0.9) + Big Kill ([8/13]*0.9) = 0.66 + 0.55 = 1.21 (rounding to 1.2)

http://www.tf2outpost.com/trade/24369054

http://i.imgur.com/a2XP3we.png → http://i.imgur.com/xSx7Gt4.png

Sale 2:

Sold for 15 keys (14.5/15) = 0.97 (rounding to 1)

http://www.tf2outpost.com/trade/24413298

http://backpack.tf/profiles/76561198042679518?time=1420099200 → http://backpack.tf/profiles/76561198042679518?time=1420272000

Sale 3: (invalid sale, unpriced hats)

Sold with PE Combover + Nuts Combover for Vintage Alien Swarm Parasite

http://backpack.tf/profiles/76561198121873144?time=1420444800 → http://backpack.tf/profiles/76561198121873144?time=1420531200

Sale 4: (invalid sale, outlier)

Sold with Planets Brainiac + Nuts Combover + 1 bud for Mega Strike RPS

http://backpack.tf/profiles/76561198017387417?time=1420704000 → http://backpack.tf/profiles/76561198017387417?time=1420790400

*Mini for Stormy Storm Dread Knot:

http://www.tf2outpost.com/trade/24417190 - Sold for 9 keys

http://i.imgur.com/X1Yc7tR.png - B/O of 10 keys

http://www.tf2outpost.com/trade/24421296 - B/O of 10 keys

~ Taking a value of 9.5 keys.

Notes:

For valuing the buds, I'm using the price at the time of sale.

Feel free to support/counter my suggestion!