Suggestion 22. Squad 1.

Untrace

https://backpack.tf/profiles/76561199006272610#!/compare/1601856000/1605744000

https://backpack.tf/profiles/76561198139370347#!/compare/1601683200/1601856000

Untrace

https://backpack.tf/profiles/76561198260686830#!/compare/1601337600/1601337600

https://backpack.tf/profiles/76561198850121720#!/compare/1601251200/1601337600

Untrace

https://backpack.tf/profiles/76561198850121720#!/compare/1601596800/1601683200

Sold for 8 keys + 35.77 refined

https://backpack.tf/profiles/76561199008748726#!/compare/1605916800/1606608000

https://backpack.tf/profiles/76561198139370347#!/compare/1606521600/1606608000

Taking Keys value from https://bot.tf/stats/listings/4RDN2NP5 - 59.66 ref

Rounding this into 8.5 Keys

Marketplace sales

https://marketplace.tf/items/tf2/213;5;u32

November 19 - $19.99 / $1.75 = 11.42 Keys (11 Keys)

December 13 - $19.99 / $1.92 = 10.41 keys (10 Keys)

Classifieds

https://gyazo.com/48748766a489e70d39bdd1596488f199

Summary

Sales at 8.5, 10.5, and 11.

Conclusion

Buyers up to 8.7~, excluding 8.5.

Going with 10-11 here.