Countering.

Sale 1: Bulk.

https://backpack.tf/profiles/76561198264117106#!/compare/1551744000/1551916800

https://backpack.tf/profiles/76561198153789411#!/compare/1551830400/1551916800

Sale 2: Use There.

Sold With Strange Professional Killstreak Australium Force-A-Nature For White Lightning Blast Defense.

https://backpack.tf/profiles/76561198153789411#!/compare/1551916800/1552003200

https://backpack.tf/profiles/76561198013245606#!/compare/1551916800/1552003200

Sale 3: ~51 Keys.

Sold For Searing Plasma Hustler's Hallmark (39) + Potassium Bonnett (12) = 51 keys.

https://backpack.tf/profiles/76561198013245606#!/compare/1552348800/1552435200

https://backpack.tf/profiles/76561198047941585#!/compare/1552348800/1552435200

Mini For Duped Searing Plasma Hustler's Hallmark:

https://marketplace.tf/items/146;5;u15

May 28

$69.99 / $1.81 = 38.67 keys. ~39 Keys

https://gyazo.com/ac5e04e04ad171d28b2c6f224ebf1566 - https://backpack.tf/item/178093706

~39 Keys.

Sale 4: Bulk.

https://backpack.tf/profiles/76561198006295346#!/compare/1555113600/1555200000

https://backpack.tf/profiles/76561198025560677#!/compare/1554508800/1555113600

Only usable sale : 51

Going with 51 keys flat.

Thanks to scourge for the premium!