History 1: https://backpack.tf/item/6643473780

15 keys:

https://backpack.tf/profiles/76561198077625769#!/compare/1635120000/1635206400

https://backpack.tf/profiles/76561198799242120#!/compare/1635206400/1637107200

History 2: https://backpack.tf/item/8459812195

Dumped to Quicksell.Store:

https://backpack.tf/profiles/76561198965070085#!/compare/1633392000/1633737600

https://backpack.tf/profiles/76561199084784906#!/compare/1633305600/1633392000

Alongside a Spec KS Pan for 18 keys (credit to FishCrimes):

https://backpack.tf/profiles/76561199084784906#!/compare/1635465600/1635552000

https://backpack.tf/profiles/76561198297177016#!/compare/1635379200/1635638400

https://backpack.tf/item/4484506585

Buyout was 16 keys 30 ref https://gladiator.tf/listings/617b45dd5da7daf662c2fd68 (thanks Shubble Skeek)

https://gladiator.tf/listings/617b4618cfe4e37662f0acd1 keys were ~57 ref

https://gladiator.tf/sales?item=Specialized%20Killstreak%20Frying%20Pan&at=2021-10-29T09:22:46.799Z

Pan was selling for ~1 key 28 at the time of the sale, which is 1.49 keys

The 16 key 30 ref buyout for the Luxury Lounge equals to 16.52 keys.

So with this, the sale is actually 18-1.49=16.51 keys, which rounds to 17

Taking 15-17 keys here