time to steal, thanks erik ;3

Sale 1)

Marketplace sale at $70

$70 / $1.74 = 40.23 keys

https://manic.tf/keyprice/?at=2018-11-16

https://marketplace.tf/items/30549;5;u56

Sale2) - 37

https://backpack.tf/item/6995220347

https://backpack.tf/profiles/76561198149867416#!/compare/1546732800/1546905600

https://backpack.tf/profiles/76561198016070169#!/compare/1546819200/1546905600

https://backpack.tf/profiles/76561198074924284#!/compare/1546905600/1546992000

https://backpack.tf/profiles/76561198238166694#!/compare/1546905600/1546992000

Sold for a Strange Purple Energy Fatman's Field Cat + Holy Grail Taunt: Second Rate Sorcery + ~2 keys.

https://backpack.tf/profiles/76561198074924284#!/compare/1545350400/1545523200

https://backpack.tf/profiles/76561198041056539#!/compare/1545264000/1545436800

Bulk-ish, wouldn't use here.

https://backpack.tf/profiles/76561198080179568#!/compare/1545091200/1545177600

https://backpack.tf/profiles/76561198041056539#!/compare/1545091200/1545177600

Seems to have sold for 29 keys. ID's match.

https://backpack.tf/profiles/76561198064982470#!/compare/1548720000/1548806400

https://backpack.tf/profiles/76561198134266699#!/compare/1548720000/1548806400

Bulk.

https://backpack.tf/profiles/76561198095236132#!/compare/1548720000/1548806400

https://backpack.tf/profiles/76561198134266699#!/compare/1548720000/1548806400

Bulk.

https://backpack.tf/profiles/76561198083000445#!/compare/1548028800/1548115200

https://backpack.tf/profiles/76561198095236132#!/compare/1548028800/1548115200

Bulk.

https://backpack.tf/profiles/76561198304476963#!/compare/1547769600/1547856000

https://backpack.tf/profiles/76561198083000445#!/compare/1547769600/1547856000

Sold for 27 keys + ~1 key mixed.

https://backpack.tf/profiles/76561198304476963#!/compare/1547596800/1547683200

https://backpack.tf/profiles/76561198113084770#!/compare/1547510400/1547683200

Sold for 27 keys.

Classifieds: https://gyazo.com/01d194a3c05946b6a9707c83e37a6c36

The 40 key marketplace sale is somewhat old now though would support a high end of 38 keys. 27 is a bit low compared to buyers. 28-37 seems ok here, a bit of a wide range but it represents all sales.