Item 1: https://backpack.tf/item/5091819418

Sale 1: https://marketplace.tf/items/tf2/779;5;u30

64.99$ / 1.74 = 37.35 keys = 37 keys

Item 2: https://backpack.tf/item/2646579897

Sale 1: partial trace.

https://backpack.tf/profiles/76561199084784906#!/compare/1645920000/1646006400

https://backpack.tf/profiles/76561198140316312#!/compare/1645833600/1645920000

Sale 2: 50 keys.

unable to trace as the item seems to have been painted soon after purchase.

However, the buyer confirmed it was bought for 50 keys.

https://freeimage.host/i/screenshot-2022-05-07-80513-am.W1ReyX

https://backpack.tf/profiles/76561198140316312#!/compare/1647648000/1647734400

https://backpack.tf/profiles/76561198110825306#!/compare/1647648000/1647734400

37 - 50 keys should do.

I have excluded duped sales. Although one of them is not traceable and other sale is about the same price as lower-end price of clean ones.