Hm.

Sale 1: Unknown

https://backpack.tf/profiles/76561198337734785#!/compare/1583884800/1583971200

https://backpack.tf/profiles/76561198354459626#!/compare/1583798400/1583884800

Sale 2, 3, 4 & 5: Marketplace

https://marketplace.tf/items/tf2/481;5;u33

https://backpack.tf/item/3361440718

9.36 on March 11, 2020 (9.36/1.72 = 5.44 rounding to 5.5 keys)

10 on March 22, 2020 (10/1.68 = 5.95 rounding to 6 keys)

14 on May 13, 2020 (14/1.9 = 7.36 rounding to 7.5 keys)

14 on May 14, 2020 (14/1.9 = 7.36 rounding to 7.5 keys)

Sale 6: Unknown

https://backpack.tf/profiles/76561198020673987#!/compare/1585958400/1586044800

https://backpack.tf/profiles/76561198337734785#!/compare/1585958400/1585872000

Classifieds:

https://gyazo.com/71917ec2167c287a713545c5f1238623

Sales at 5.5, 6, 7.5, and 7.5. Buyers are at 5.93+. Excluding 5.5. 6 seems quite low too, because it was rounded from 5.95 and buyers are literally 0.02 away. Excluding 6 as well.

Taking 7.5 keys here.