History 1: https://backpack.tf/item/9435701616

22 keys:

https://backpack.tf/profiles/76561198003724587#!/compare/1610409600/1610496000

https://backpack.tf/profiles/76561199069175223#!/compare/1610323200/1610496000

Sold with 4 keys for a Strange Professional Killstreak Australium Scattergun:

https://backpack.tf/profiles/76561199069175223#!/compare/1610755200/1610841600

https://backpack.tf/profiles/76561198137532952#!/compare/1610668800/1610841600

56-57 should be fine for the value of the Scattergun https://imgur.com/Fs1tOgj https://imgur.com/iqwmUAc

56.5-4=52.5 ~53 keys. No buyout

History 2: https://backpack.tf/item/9381705781

20 keys 23 ref, ~20 keys, same matches in buyer's compare:

https://backpack.tf/profiles/76561198052766593#!/compare/1614729600/1614816000

https://backpack.tf/profiles/76561198074924284#!/compare/1614643200/1614729600

One sold on Marketplace.tf, can't trace the history: https://marketplace.tf/items/tf2/30969;5;u163

December 10: $49.99/1.81=27.62 ~28 keys

Unsolds: A seller at 50 has been there for 20 days https://backpack.tf/item/9374310852

Sales at 20, 23, 28, 53.

Given the unsold at 50 for a while and the fact the manority of the sales have happened in the 20-28 range, 53 looks like an outlier here.

Gonna go with 20-28