Item 1:

https://backpack.tf/item/9819483674

Sale 1:

https://backpack.tf/profiles/76561198060126263#!/compare/1756512000/1756598400

https://backpack.tf/profiles/76561199059800460#!/compare/1756512000/1756598400

Untrace

Item 2:

https://backpack.tf/item/12122723387

Sale 2:

https://backpack.tf/profiles/76561198339153940#!/compare/1754784000/1755302400

https://backpack.tf/profiles/76561199014821490#!/compare/1755129600/1755561600

Sold for 15 keys pure (ID 16053438394)

Item 3:

https://backpack.tf/item/5060408889

Sale 3 & 4:

https://marketplace.tf/items/tf2/1162;5;u3091

Sold for $34.99 on the 15th of Aug and 6th of Sep

Keys were:

https://marketplace.tf/items/tf2/5021;6

15th - $1.81 (34.99/1.81) = 19.3 (Rounding down to 19)

6th - $1.8 (34.99/1.8) = 19.43 (Rounding down to 19)

//

Sellers:

BPTF - None (1 listed on MP as per below)

MPTF - https://marketplace.tf/items/tf2/1162;5;u3091 - $34.99

STN - https://stntrading.eu/item/tf2/Unusual+Blazed+Brew+Taunt%3A+Mannrobics - None

SCM - https://steamcommunity.com/market/listings/440/Unusual%20Taunt%3A%20Mannrobics?filter=Blazed+Brew - None

Sale(s):

15, 19, 19

Excluding 15 keys due to buyers (including STN) are buying for more. Plus it was a buy order currently listed.

Going with 19 keys flat