Using last 3 months.

Sale 1:

Sold for 9 keys

https://backpack.tf/profiles/76561199581722058#!/compare/1706313600/1706400000

https://backpack.tf/profiles/76561198364475021#!/compare/1706313600/1706400000

https://backpack.tf/item/1541059420

= 9 keys

Sale 2:

Sold for 8 keys (buyer’s end)

https://backpack.tf/profiles/76561198203316140#!/compare/1708473600/1708560000

https://backpack.tf/profiles/76561198151373000#!/compare/1708560000/1708646400

https://backpack.tf/item/5962836236

= 8 keys

Sale 3:

Sold to a bot for 7 keys + ~1 key in metal

https://backpack.tf/profiles/76561198067540052#!/compare/1706227200/1706313600

https://backpack.tf/profiles/76561199111073161#!/compare/1706227200/1706313600

https://backpack.tf/item/1483143631

= 8 keys

Sale 4:

Sold to a bot for 7 keys + 30 ref (~7.5 keys)

https://backpack.tf/profiles/76561198058063358#!/compare/1706572800/1706659200

https://backpack.tf/profiles/76561199139085248#!/compare/1706572800/1706659200

https://gladiator.tf/sales?item=Holy%20Grail%20Shred%20Alert&at=2024-01-31T12:11:46.833Z - confirmed

https://backpack.tf/item/9597499726

= 7.5 keys

Sale 5:

Sold for 7 keys + 28 ref (~7.5 keys)

https://backpack.tf/profiles/76561198144204860#!/compare/1712707200/1712793600

https://backpack.tf/profiles/76561198163615254#!/compare/1712620800/1712707200

https://backpack.tf/item/1474403725

= 7.5 keys

Other Sales:

#1

https://backpack.tf/profiles/76561198197345478#!/compare/1711756800/1711929600

https://backpack.tf/profiles/76561198311498888#!/compare/1711843200/1711929600

https://backpack.tf/item/13889404735

Untraceable

#2

https://backpack.tf/profiles/76561198311498888#!/compare/1711843200/1711929600

https://backpack.tf/profiles/76561199069442401#!/compare/1711929600/1712016000

https://backpack.tf/item/13889404735

Bulk for keys

#3

https://backpack.tf/profiles/76561199581722058#!/compare/1708214400/1708300800

https://backpack.tf/profiles/76561199081216584#!/compare/1705795200/1712188800

https://backpack.tf/item/12561315432

Untraceable

#4

https://backpack.tf/profiles/76561199486426020#!/compare/1709078400/1709337600

https://backpack.tf/profiles/76561198125896125#!/compare/1709251200/1709424000

https://backpack.tf/item/12497320611

Untraceable

#5

https://backpack.tf/profiles/76561198125896125#!/compare/1709424000/1709510400

https://backpack.tf/profiles/76561198046257607#!/compare/1656720000/1711670400

https://backpack.tf/item/12497320611

Untraceable

#6

https://backpack.tf/profiles/76561198151373000#!/compare/1708646400/1708732800

https://backpack.tf/profiles/76561197972024184#!/compare/1700956800/1708992000

https://backpack.tf/item/5962836236

Untraceable/Bulk

#7

https://backpack.tf/profiles/76561198163116848#!/compare/1711324800/1711756800

https://backpack.tf/profiles/76561198261483133#!/compare/1711670400/1711756800

https://backpack.tf/item/1735059765

Backpack buy

#8

https://backpack.tf/profiles/76561199157918922#!/compare/1706054400/1706745600

https://backpack.tf/profiles/76561199581722058#!/compare/1705968000/1706054400

https://backpack.tf/item/1541059420

Untraceable

#9

https://backpack.tf/profiles/76561198364475021#!/compare/1706313600/1706400000

https://backpack.tf/profiles/76561199026390261#!/compare/1706400000/1706486400

https://backpack.tf/item/1541059420

Untraceable. This follows the 9 key sale.

#10

https://backpack.tf/profiles/76561199026390261#!/compare/1707350400/1707436800

https://backpack.tf/profiles/76561198414837199#!/compare/1706659200/1707609600

https://backpack.tf/item/1541059420

Bulk for keys

#11

https://backpack.tf/profiles/76561198414837199#!/compare/1707609600/1707782400

https://backpack.tf/profiles/76561198950650033#!/compare/1697155200/1711670400

https://backpack.tf/item/1541059420

Untraceable

#12

https://backpack.tf/profiles/76561198850178158#!/compare/1708387200/1708473600

https://backpack.tf/profiles/76561198268970494#!/compare/1708387200/1708473600

https://backpack.tf/item/1486364215

Untraceable

#13

https://backpack.tf/profiles/76561198268970494#!/compare/1708473600/1708560000

https://backpack.tf/profiles/76561199084784906#!/compare/1708473600/1708560000

https://backpack.tf/item/1486364215

Untraceable

#14

https://backpack.tf/profiles/76561199084784906#!/compare/1708646400/1708732800

https://backpack.tf/profiles/76561198215458333#!/compare/1707955200/1708905600

https://backpack.tf/item/1486364215

Untraceable

#15

https://backpack.tf/profiles/76561199111073161#!/compare/1706832000/1706918400

https://backpack.tf/profiles/76561198130555561#!/compare/1706832000/1706918400

https://backpack.tf/item/1483143631

Untraceable. Appears to have been scammed afterwards.

#16

https://backpack.tf/profiles/76561198254582506#!/compare/1703203200/1711670400

https://backpack.tf/profiles/76561198132808609#!/compare/1711497600/1711670400

https://backpack.tf/item/4458133901

Backpack buy

#17

https://backpack.tf/profiles/76561199101242754#!/compare/1712966400/1713052800

https://backpack.tf/profiles/76561199444670698#!/compare/1713052800/1713657600 - no better compare link

https://backpack.tf/item/1473473540

Probably scammed

#18

https://backpack.tf/profiles/76561199444670698#!/compare/1713052800/1713657600

https://backpack.tf/profiles/76561199522478149#!/compare/1712966400/1713052800

https://backpack.tf/item/1473473540

Untraceable

#19

https://backpack.tf/profiles/76561199522478149#!/compare/1713052800/1713139200

https://backpack.tf/profiles/76561199183171982#!/compare/1713052800/1713139200

https://backpack.tf/item/1473473540

Backpack buy, probably off a fence

https://backpack.tf/item/12621546108 - marketplace

https://backpack.tf/item/11401494575 - marketplace

https://backpack.tf/item/3986616955 - bot transfer

https://backpack.tf/item/2237458715 - marketplace

https://backpack.tf/item/2208172693 - marketplace

Marketplace Sales:

https://marketplace.tf/items/tf2/1015;5;u3003

$22.99, Feb 9th, 25th, March 15th, & 29th

https://marketplace.tf/items/tf2/5021;6 - Keys were:

$1.70, Feb 9th & 25th

$1.67, March 15th & 29th

22.99/1.7 = 13.524, rounds to 14 (2x)

22.99/1.67 = 13.766, rounds to 14 (2x)

Sellers:

https://imgur.com/a/PWmx9q7

https://backpack.tf/item/9597499726 - 12 keys

https://backpack.tf/item/1735059765 - 12 keys

https://backpack.tf/item/3986616955 - 15 keys

https://backpack.tf/item/1529304139 - marketplace

https://backpack.tf/item/6952264372 - marketplace

https://backpack.tf/item/11048114966 - marketplace

https://backpack.tf/item/13889404735 - marketplace

https://backpack.tf/item/1473724878 - marketplace

https://backpack.tf/item/1488274128 - marketplace

https://backpack.tf/item/4458133901 - marketplace

https://backpack.tf/item/1473473540 - marketplace

Sales at:

7.5 (2x)

8 (2x)

9

14 (4x, marketplace)

The marketplace sales at 14 are higher than current listings, as well as current marketplace sellers, with 6 of them now selling for $21. Excluding 14.

Taking 7.5-9 keys.