This way to Quizno's!

Sale for 4 keys:

https://i.gyazo.com/cb8455c4e76faa23ed3bd21282352d5f.png

Seller for 3.7 keys in classifieds:

https://i.gyazo.com/8683f3f55b753b164664d0ac2e038974.png

A lot of these exist so I wouldn't be surprised if there were more sales. Feel free to leave a comment with more evidence and I'll be happy to resuggest if it doesn't support this range.

Cheers!

I got premium so I might as well look at the other sales

Item 1

https://backpack.tf/item/9550674993

Sale 1: Bulk

Seller: https://backpack.tf/profiles/76561199099521803#!/compare/1728864000/1729036800

Buyer: https://backpack.tf/profiles/76561199416984046 (Not bumped enough)

Sale 2: Bulk

Seller: https://backpack.tf/profiles/76561199581722058#!/compare/1728864000/1728950400

Buyer: https://backpack.tf/profiles/76561199099521803#!/compare/1728691200/1728864000

Sale 3: Untraceable

Seller: https://backpack.tf/profiles/76561199250992747#!/compare/1728172800/1728691200

Buyer: https://backpack.tf/profiles/76561199581722058#!/compare/1728172800/1728259200

Sale 4: Untraceable

Seller: https://backpack.tf/profiles/76561199026390261#!/compare/1728000000/1728086400

Buyer: https://backpack.tf/profiles/76561199250992747#!/compare/1728086400/1728172800

Sale 5: Bulk

Buyer: https://backpack.tf/profiles/76561198161842059#!/compare/1725753600/1725840000

Seller: https://backpack.tf/profiles/76561199026390261#!/compare/1725840000/1725926400

Item 2

https://backpack.tf/item/9579935885

Sale 1: Bulk

Seller: https://backpack.tf/profiles/76561198983856237#!/compare/1730073600/1730160000

Buyer: https://backpack.tf/profiles/76561198312305282#!/compare/1729728000/1730851200

Marketplace.tf page: https://marketplace.tf/items/tf2/31161;5;u3066

All currently at $9.99; no sales in the last three years

Just to be thorough I also check a couple as far back as August. They're outdated but maybe they can help somehow:

Item 3

https://backpack.tf/item/9637608212

Sale 1: Bot sale for 2 keys 10.11 ref

Seller: https://backpack.tf/profiles/76561199059160806#!/compare/1723593600/1723680000 (Look at key history)

Buyer: https://backpack.tf/profiles/76561199059160806#!/compare/1723593600/1723680000

Item 4

https://backpack.tf/item/10815212154

Sale 1: Bulk

Seller: https://backpack.tf/profiles/76561199751344627#!/compare/1724630400/1724803200

Buyer: https://backpack.tf/profiles/76561198125937591#!/compare/1724716800/1724803200

Sale 2: Bulk

Seller: https://backpack.tf/profiles/76561199591440178#!/compare/1724457600/1724716800

Buyer: https://backpack.tf/profiles/76561199751344627#!/compare/1724630400/1724630400 (History starts with this item already in their backpack)

I couldn't find any other that changed hands in the last three months aside from moving them to Marketplace bots.

The seller in classifieds has also lowered to 3.6 keys though.