Oh boy, here we go...

Hat 1:

Sale 1 = Invalid

https://backpack.tf/profiles/76561198042039330#!/compare/1526256000/1526342400

https://backpack.tf/profiles/76561198830746853#!/compare/1526256000/1526342400

1 for 1 for a Blizzardy Storm Bonk Helm. Already used to price the Helm, this is the Mini.

Sale 2:

https://backpack.tf/profiles/76561198830746853#!/compare/1527206400/1527292800

Sold for 16 keys

Hat 2:

Sale 1:

https://backpack.tf/profiles/76561198095433550#!/compare/1527206400/1527292800

https://backpack.tf/profiles/76561198082613857#!/compare/1527033600/1527379200

Sold for 15 keys + a few ref in items = 15 keys

Sale 2:

Sold with a Purple Confetti Antarctic Eyewear for a Strange Searing Plasma Runner's Warm-Up

https://backpack.tf/profiles/76561198323401829#!/compare/1528416000/1528502400

https://backpack.tf/profiles/76561198082613857#!/compare/1528416000/1528502400

Should be used for the Runner's Warm-Up.

Hat 3:

Sale 1:

https://backpack.tf/profiles/76561197967159739#!/compare/1523750400/1523836800

https://backpack.tf/profiles/76561198145263145#!/compare/1523750400/1524268800

Sold for 16 keys pure

Hat 4:

Sale 1:

https://backpack.tf/profiles/76561198179285485#!/compare/1524873600/1525046400

Sold for 13 keys

Hat 5:

Sale 1:

Sold for a Dead presidents Runner's Warm-Up (Mini below) + ~2 keys in items

https://backpack.tf/profiles/76561198399964746#!/compare/1524182400/1524268800

https://backpack.tf/profiles/76561198335171238#!/compare/1524268800/1524614400

No Mini available, excluding.

Sale 2:

Sold with a Bubbling A Hat To Kill For for a Starstorm Insomnia Towering Pillar of Hats

https://backpack.tf/profiles/76561198335171238#!/compare/1524614400/1524787200

https://backpack.tf/profiles/76561197964171516#!/compare/1524528000/1524614400

Should be used to price the Towering Pillar of Hats

Buyers/Sellers: https://gyazo.com/0060e3259d1061b12a6142eb818a4d19

Sales: 13 / 15 / 16 / 16

Excluding 13, cause it's countered by buyers.

3 sellers unsold at 17, all unsold for 3 days, 12 days and a month.

Taking 15-16 keys