Sold for 70 pure keys (histories match, I'm guessing seller pulled it off steam market and quickly sold to buyer):

https://backpack.tf/item/389775003

https://backpack.tf/profiles/76561197978308259#!/compare/1524614400/1524873600

Sold for 69 Keys:

https://backpack.tf/profiles/76561198024925599#!/compare/1518220800/1518307200

Sold with 6 Keys for Burning Brain Bucket (needs an update, currently too low):

https://backpack.tf/profiles/76561198059607762#!/compare/1520294400/1520380800

Sold for unusual sniper rifle + 15 keys + 1 key in sweets:

https://backpack.tf/profiles/76561198136987862#!/compare/1520726400/1520812800

(

Rifle mini:

Sold for beams puffy:

https://backpack.tf/profiles/76561198170371903#!/compare/1517788800/1517961600

Sold for sfb combustible:

https://backpack.tf/profiles/76561198219980724#!/compare/1520380800/1520640000

Sold for... 75 pure?:

https://backpack.tf/profiles/76561198136987862#!/compare/1521849600/1521936000

Sold for... 34 pure?:

https://backpack.tf/profiles/76561198111475184#!/compare/1522972800/1523145600

)

I honestly don't know, excluding this sale.