Credits to Bray for letting me know

Golden Frying Pan plus 1100 keys for Duped Darkblaze Killer Exclusive and a Purple Dead of Night.

https://backpack.tf/item/2035552221

Seller: https://backpack.tf/profiles/76561198027338258#!/compare/1666224000/1666915200

Buyer: https://backpack.tf/profiles/76561198822773578#!/compare/1666224000/1666915200

Mini for Golden Frying Pan

1a) Sold on October 29 for $6118.96 USD

https://mannco.store/item/440-mann-co-supply-crate-key keys were at $1.81 on October 29.

6118.96/$1.81= ~ 3380 keys

2a) Sold on November 2 for $6117 USD

https://mannco.store/item/440-mann-co-supply-crate-key were at $1.83 on November 2.

6117/1.83 = ~3341 keys = ~ 3300 keys

3a) Sold for $6295 on November 7

https://mannco.store/item/440-mann-co-supply-crate-key Keys were at $1.89 on November 7.

6295/1.89 = ~ 3330 keys = ~ 3300 keys

(3330+3341+3380)/3 = 3350.33 = ~3300 keys

3300+1100=4400 keys

Going 4400 keys flat