-First person in the history obtaining the hat is untraceable: https://backpack.tf/profiles/76561198451503538#!/compare/1642032000/1642377600

-9k 14ref: https://backpack.tf/profiles/76561198451503538#!/compare/1642377600/1642464000 https://backpack.tf/profiles/76561198395837984#!/compare/1642377600/1642464000

-10k, ~25 ref: https://backpack.tf/profiles/76561198395837984#!/compare/1642464000/1642550400 https://backpack.tf/profiles/76561199215748094#!/compare/1642464000/1642550400

-11 keys, see buyer end: https://backpack.tf/profiles/76561199215748094#!/compare/1642636800/1642723200 https://backpack.tf/profiles/76561199185696636#!/compare/1642636800/1642723200

-13 keys; buyer got keys from selling taunt and immediately bought this hat: https://backpack.tf/profiles/76561199185696636#!/compare/1642636800/1642723200 https://backpack.tf/profiles/76561198799292625#!/compare/1642723200/1643414400

So buyers are at 11 now, and with a sale at 11, one at like ~10.35, and one at 12, I think 11 is decently supported- not to mention the sub-10 sale. I think 11-13 is the call