Resuggesting, thank you K1ng!

Sale 1: 57 keys match in ID's

https://backpack.tf/profiles/76561198002757046#!/compare/1586822400/1586908800

https://backpack.tf/profiles/76561198028005808#!/compare/1586649600/1586908800

Key ID's match, but buyout was 45 keys

https://bot.tf/stats/listings/4KVJ5VWE

Sale 2: Sold for 39 keys + 33 refined

https://backpack.tf/profiles/76561198075970209#!/compare/1584662400/1585353600

https://backpack.tf/profiles/76561198002757046#!/compare/1584576000/1584662400

Rounds to 40 keys

Sale 3 & 4: Marketplace

https://marketplace.tf/items/tf2/104;5;u14

https://backpack.tf/item/7957011234 (Sale 3?)

https://backpack.tf/item/178668215 (Sale 4)

55.75 on April 28, 2020 (55.75/1.82 = 30.63 rounding to 31 keys)

104.99 on May 8, 2020 (104.99/1.89 = 55.55 rounding to 56 keys)

Classifieds:

https://gyazo.com/2b4d809d96afe525cd0df7f7ed554920

Sales at 31, 40, 45, and 56. Buyers at 40+. Excluding 31 and 40.

Taking a range of 45-56 keys here.