Item 1: https://backpack.tf/item/2206355131

Sale 1:

https://backpack.tf/profiles/76561199203680409#!/compare/1767916800/1768003200

https://backpack.tf/profiles/76561198255414077#!/compare/1767657600/1768262400

10 keys 31 ref, with the current key price that makes the ref part 0.53 keys so the sale will round to 11

Item 2: https://backpack.tf/item/3404001203

Sale 2:

https://backpack.tf/profiles/76561199851431130#!/compare/1767139200/1771372800

https://backpack.tf/profiles/76561198850274253#!/compare/1767052800/1767139200

Dumped to Quciksell.tore, untrace

Sale 3:

https://backpack.tf/profiles/76561198850274253#!/compare/1767571200/1767657600

https://backpack.tf/profiles/76561198806109184#!/compare/1767571200/1767657600

I see 18 keys that match via histories in the buyer's compare

Sale 4:

Sold via Mannco.Store hen dumped to a bot which is currently listed at 15 keys, unusable regardless

Sales

11, 18

Sellers:

BPTF - https://imgur.com/Kq4k5HO 15 keys (1 month)

MPTF - https://marketplace.tf/items/tf2/30022;5;u62 none

STN - https://stntrading.eu/item/tf2/Unusual+Disco+Beat+Down+Plumber%27s+Pipe none

SCM - https://steamcommunity.com/market/listings/440/Unusual%20Plumber%27s%20Pipe?filter=Disco+Beat+Down https://imgur.com/CpxCb3l 29.99€ (~15 keys)

If the 18 key sale is correct, it will end up being an outlier with both the sellers at 15 keys. Going with 11 keys flat