https://backpack.tf/item/2214919200

https://backpack.tf/profiles/76561198336605191#!/compare/1626566400/1626652800

Sale for Open Mind Patriot Peak, use there.

https://backpack.tf/profiles/76561198360763678#!/compare/1633392000/1633478400

https://backpack.tf/profiles/76561198069707880#!/compare/1633305600/1633651200

Can't really trace.

https://backpack.tf/item/8597636504

https://backpack.tf/profiles/76561199059840687#!/compare/1629763200/1629849600

https://backpack.tf/profiles/76561198047988243#!/compare/1629763200/1629849600

67 keys match.

https://backpack.tf/item/7957594698

https://backpack.tf/profiles/76561198841279602#!/compare/1629244800/1629331200

https://backpack.tf/profiles/76561198142093134#!/compare/1629244800/1629331200

Unclear, it looks like the buyer quicksold some stuff for pure to buy this. A 67 key trade matches on the seller's end, so it's possible this could also be 67 keys.

https://gladiator.tf/sales?item=Kill-a-Watt%20Team%20Captain&at=2021-10-17T14:52:21.560Z

Recent sale at buyer orders for ~63 keys. I'll include it in range given it's the most recent sale.

Taking 63-67 keys.