Sale 1:

https://backpack.tf/profiles/76561198363914581#!/compare/1534032000/1534118400

https://backpack.tf/profiles/76561198797842085#!/compare/1533945600/1534032000

Sold for Blizzardy Beanie(13.5), can't tell if other items are part of trade.

Sale 2:

https://backpack.tf/profiles/76561198055986025#!/compare/1524268800/1534377600

https://backpack.tf/profiles/76561198797842085#!/compare/1534118400/1534377600

Sold for GE Sky High + ~2 keys in sweets

Sky High Mini:

https://backpack.tf/suggestion/5b888277cf6c7568c065959a

Suggestion for 21 keys

Total is 19 keys

Sale 3:

https://backpack.tf/profiles/76561198055986025#!/compare/1534550400/1534636800

https://backpack.tf/profiles/76561198141654425#!/compare/1534291200/1534550400

Sold for Stormy Defiant(14.5) + 4 keys

Total is 18.5 keys

Sale 4:

https://backpack.tf/profiles/76561198141654425#!/compare/1534550400/1534636800

https://backpack.tf/profiles/76561198142230616#!/compare/1534550400/1534636800

Sold for 17 keys

Sale 5:

https://backpack.tf/profiles/76561198142230616#!/compare/1534636800/1534809600

https://backpack.tf/profiles/76561198177872379#!/compare/1534636800/1534723200

Sold for 17 keys + negligible sweets

Sale 6:

https://backpack.tf/profiles/76561198177872379#!/compare/1534636800/1534723200

https://backpack.tf/profiles/76561198211885115#!/compare/1534636800/1534723200

Sold for Smoking Noble(15) + ~4 keys in sweets

Total is 19 keys

Total sales @:

13.5, 17, 17, 18.5, 19, 19 keys

Buyers up to ~16 keys

Let's take 17 - 19 keys.