Re-suggesting, using sales from the last suggestion onwards.

Sale 1:

Sold for 3 keys + 23 ref

https://backpack.tf/profiles/76561198311498888#!/compare/1710460800/1710547200

https://backpack.tf/profiles/76561198068068814#!/compare/1710460800/1710547200

https://backpack.tf/item/12823489523

= 3.35 keys

Sale 2:

Sold to a bot for 2 keys + 9 ref

https://backpack.tf/profiles/76561199193933005#!/compare/1708041600/1708387200

https://backpack.tf/profiles/76561199521823568#!/compare/1708300800/1708387200

https://backpack.tf/item/14106535721

= 2.15 keys

Other Sales:

https://backpack.tf/profiles/76561198211822291#!/compare/1715472000/1715817600

https://backpack.tf/profiles/76561199059698603#!/compare/1715731200/1715817600

https://backpack.tf/item/12227909647

Bulk to Quicksell.store

https://backpack.tf/item/12963566514 - marketplace

https://backpack.tf/item/12347525093 - unusualified

https://backpack.tf/item/12286745243 - marketplace

Marketplace Sales:

https://marketplace.tf/items/tf2/31286;5;u3003

$8.99, May 6th & May 19th

https://backpack.tf/item/14106535721 - May 6th, unscanned

https://backpack.tf/item/12963566514 - May 19th, dumped to bot immediately after

Excluding May 19th as it's now invalid.

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

Keys were $1.65, May 6th

8.99/1.65 = ~5.45 keys

Sellers:

https://imgur.com/a/r21VLp8

https://backpack.tf/item/12227909647 - ~5.5 keys

Sales at:

2.15

3.35

5.45

2.15 is a lone sale to a bot. STN is currently paying a little higher. Should be fine to exclude.

https://stntrading.eu/item/tf2/Unusual+Holy+Grail+Taunt%3A+Texas+Twirl+%27Em

https://imgur.com/a/623FILg

Average value is below 5 keys, rounding to the nearest 0.05 keys here.

Taking 3.35-5.45 keys.

https://backpack.tf/profiles/76561198350276363#!/compare/1717459200/1718064000

https://backpack.tf/profiles/76561199099031605#!/compare/1717977600/1718064000

https://gladiator.tf/sales?item=Holy%20Grail%20Taunt:%20Texas%20Twirl%20%27Em&at=2024-06-12T10:30:25.458Z - labelled as 2 keys + 3 ref

https://backpack.tf/item/14200003910

1 key + 3 ref match, should be safe to assume Gladiator is correct here.