Sale 1:

https://backpack.tf/profiles/76561198043167758#!/compare/1546819200/1566345600

https://backpack.tf/profiles/76561198153400625#!/compare/1571788800/1572134400

SCM

sale 2:

https://backpack.tf/profiles/76561198356548106#!/compare/1566345600/1566432000

https://backpack.tf/profiles/76561198057895234#!/compare/1566432000/1568678400

Untrace

sale 3:

https://backpack.tf/profiles/76561198089253101#!/compare/1566086400/1566172800

https://backpack.tf/profiles/76561197994587943#!/compare/1566086400/1566172800

Untrace

Sale 4:

https://backpack.tf/profiles/76561198061667387#!/compare/1567209600/1567728000

https://backpack.tf/profiles/76561198165205268#!/compare/1567555200/1567641600

Sold with 3 keys for Miami Tyrantium(14.5)

Total is 11.5 keys

Sale 5:

https://backpack.tf/profiles/76561198165205268#!/compare/1567814400/1567900800

https://backpack.tf/profiles/76561198146992563#!/compare/1567555200/1567900800

Sold for 9 keys

sale 6:

https://backpack.tf/profiles/76561198146992563#!/compare/1567555200/1567900800

https://backpack.tf/profiles/76561198282150790#!/compare/1567814400/1567900800

Sold for G Fetti Thirst Blood + negligible sweets

Thirst Blood Mini:

https://backpack.tf/suggestion/5dcd8efb67807276c6637ab5

Suggestion for 11.5 keys

Total is ~12 keys

sale 7:

https://backpack.tf/profiles/76561198282150790#!/compare/1567900800/1567987200

https://backpack.tf/profiles/76561198275783474#!/compare/1567814400/1567987200

Sold for TW Slick

use there

sale 8:

https://backpack.tf/profiles/76561198275783474#!/compare/1567814400/1567987200

https://backpack.tf/profiles/76561198080670371#!/compare/1567900800/1567987200

bulk

sale 9:

https://backpack.tf/profiles/76561198080670371#!/compare/1567900800/1567987200

https://backpack.tf/profiles/76561198363395191#!/compare/1567900800/1567987200

QS

sale 10:

https://backpack.tf/profiles/76561198363395191#!/compare/1572912000/1572998400

https://backpack.tf/profiles/76561198059391724#!/compare/1564444800/1572998400

https://backpack.tf/profiles/76561198208827912#!/compare/1572825600/1572998400

Keys / bulk

sale 11:

https://backpack.tf/profiles/76561198208827912#!/compare/1573171200/1573257600

https://backpack.tf/profiles/76561198280275064#!/compare/1573171200/1573257600

https://backpack.tf/profiles/76561198387892741#!/compare/1573084800/1573257600

https://backpack.tf/profiles/76561198960165586#!/compare/1572825600/1573430400

https://backpack.tf/profiles/76561198064458811#!/compare/1573344000/1573430400

bulk / untrace

sale 12:

https://backpack.tf/profiles/76561198322560312#!/compare/1572307200/1573171200

https://backpack.tf/profiles/76561198048334414#!/compare/1572220800/1572307200

https://backpack.tf/profiles/76561198081965657#!/compare/1571875200/1572393600

https://backpack.tf/profiles/76561198101300189#!/compare/1572393600/1572480000

https://backpack.tf/profiles/76561198027378787#!/compare/1572307200/1572393600

https://backpack.tf/profiles/76561198878763680#!/compare/1572393600/1573171200

https://backpack.tf/profiles/76561198878820051#!/compare/1570924800/1572393600

Untrace / bulk

Sale 13:

https://marketplace.tf/items/tf2/400;5;u60

$16.67 / $1.84 = 9.06 keys <--- https://backpack.tf/item/7955685841

$15.1 / $1.82 = 8.30 keys

$17.49 / $1.81 = 9.66 keys <--- https://backpack.tf/item/7955685841

$16 / $1.76 = 9.09 keys

Total sales @:

8.30, 9.06, 9.09, 9.66, 11.5, 12 keys

buyers up to ~7 keys,

unsolds at 14 keys,

calling 8.3 the outlier,

taking 9 - 12 keys.