Resuggestion, thanks to Blaze for the info!

Sale 1:

https://backpack.tf/profiles/76561198347507959#!/compare/1578700800/1578787200

https://backpack.tf/profiles/76561198074178367#!/compare/1578700800/1578787200

Sold for 9 keys

Sale 2:

https://backpack.tf/profiles/76561198074178367#!/compare/1578787200/1578873600

https://backpack.tf/profiles/76561198286623086#!/compare/1578700800/1578787200

Sold with ~0.55 keys in sweets for 10 keys

Total is ~9.45 keys

Sale 3:

https://backpack.tf/profiles/76561198286623086#!/compare/1578700800/1578787200

https://backpack.tf/profiles/76561198319072937#!/compare/1578700800/1578787200

Untrace, probably some amount of keys.

sale 4:

https://backpack.tf/profiles/76561198319072937#!/compare/1578700800/1578787200

https://backpack.tf/profiles/76561198027857565#!/compare/1578787200/1578873600

Sold for G Fetti Warm-Up + ~2 keys in sweets

Warm up Mini:

https://backpack.tf/suggestion/5e533bcb6099fd20d24f37fa

Suggestion for 10.5 keys

Total is 12.5 keys

Sale 5:

https://backpack.tf/profiles/76561198027857565#!/compare/1578787200/1578873600

https://backpack.tf/profiles/76561198269337198#!/compare/1578700800/1578787200

Untrace

Sale 6:

https://backpack.tf/profiles/76561198269337198#!/compare/1579132800/1579219200

https://backpack.tf/profiles/76561198125791160#!/compare/1579132800/1579219200

https://backpack.tf/profiles/76561198136232046#!/compare/1579132800/1579219200

https://backpack.tf/profiles/76561198219377359#!/compare/1579132800/1579219200]

https://backpack.tf/profiles/76561198043791282#!/compare/1579132800/1579219200

Untrace / bulk

Sale 7:

https://backpack.tf/profiles/76561198043791282#!/compare/1579219200/1579305600

https://backpack.tf/profiles/76561198809414908#!/compare/1579219200/1579305600

Bulk with Aussie for Max Head

Sale 8:

https://backpack.tf/profiles/76561198809414908#!/compare/1579219200/1579305600

https://backpack.tf/profiles/76561198128940635#!/compare/1579219200/1579305600

Can trace ~5 keys, below buyers

Sale 9:

https://backpack.tf/profiles/76561198128940635#!/compare/1579478400/1579910400

https://backpack.tf/profiles/76561198809414908#!/compare/1579392000/1579478400

Sold for TW Private Eye

use there

Sale 10:

https://backpack.tf/profiles/76561198809414908#!/compare/1579392000/1579478400

https://backpack.tf/profiles/76561198055622215#!/compare/1579392000/1579478400

Bulk

Sale 11:

https://backpack.tf/profiles/76561198406394136#!/compare/1578614400/1578700800

https://backpack.tf/profiles/76561198293202095#!/compare/1565222400/1578614400

https://backpack.tf/profiles/76561198965570008#!/compare/1578614400/1578700800

https://backpack.tf/profiles/76561198053051373#!/compare/1578528000/1578700800

https://backpack.tf/profiles/76561198157836058#!/compare/1578268800/1578700800

https://backpack.tf/profiles/76561198108707942#!/compare/1578700800/1578787200

Bulk / gamble

Sale 12:

https://backpack.tf/profiles/76561198108707942#!/compare/1578960000/1579132800

https://backpack.tf/profiles/76561198063075911#!/compare/1579046400/1579132800

Bulk

sale 13:

https://backpack.tf/profiles/76561198063075911#!/compare/1579132800/1579219200

https://backpack.tf/profiles/76561198982803000#!/compare/1579219200/1581638400

https://backpack.tf/profiles/76561198882888176#!/compare/1579132800/1579219200

https://backpack.tf/profiles/76561198134797887#!/compare/1579132800/1579219200

https://backpack.tf/profiles/76561198063075911#!/compare/1579132800/1579219200

https://backpack.tf/profiles/76561198302376251#!/compare/1579132800/1579219200

https://backpack.tf/profiles/76561198882888176#!/compare/1579132800/1579219200

https://backpack.tf/profiles/76561198171672427#!/compare/1576022400/1579305600

gamble

Sale 14:

https://backpack.tf/profiles/76561198010332638#!/compare/1580428800/1580515200

https://backpack.tf/profiles/76561198396576035#!/compare/1580342400/1580515200

Sold for OF Inspecteur

Inspecteur Mini:

https://backpack.tf/suggestion/5e43787bcce65e24bf3b5d07

Suggestion for 11.5 keys

Sale 15:

https://backpack.tf/profiles/76561198396576035#!/compare/1581033600/1581552000

https://backpack.tf/profiles/76561198254524432#!/compare/1581206400/1581292800

Untrace

sale 16, 17:

https://marketplace.tf/items/tf2/701;5;u56

$30 / $1.70 = 17.65 keys

$29.99 / $1.78 = 16.85 keys <-- https://backpack.tf/item/7956238265

Total sales @:

9, 9.45, 11.5, 12.5, 16.85, 17.65 keys

buyers up to ~8 keys,

seller at 13 keys,

other sellers at ~18 keys,

gonna call 2 outliers on either end,

taking 12 - 13 keys.

Blaze's Part:

https://marketplace.tf/items/tf2/701;5;u56 - new sale at $19.44

Looks like that sale ends up being:

$19.44 / $1.72 = 11.30 keys

Some more sales:

https://backpack.tf/item/7955897044

https://backpack.tf/profiles/76561198059248968#!/compare/1584230400/1584316800

https://backpack.tf/profiles/76561198034619843#!/compare/1583971200/1584403200

Untrace

https://backpack.tf/item/6146788361

https://backpack.tf/profiles/76561198070664114#!/compare/1583712000/1583798400

https://backpack.tf/profiles/76561198337734785#!/compare/1583712000/1583798400

QS for 8 keys

https://backpack.tf/profiles/76561198337734785#!/compare/1583971200/1584057600

https://backpack.tf/profiles/76561198061353482#!/compare/1583884800/1584057600

Untrace / bulk

https://backpack.tf/item/1909323670

https://backpack.tf/profiles/76561198363395191#!/compare/1583625600/1583712000

https://backpack.tf/profiles/76561198355520251#!/compare/1583712000/1583798400

https://backpack.tf/profiles/76561198276637259#!/compare/1583798400/1583884800

https://backpack.tf/profiles/76561198281630040#!/compare/1583798400/1583884800

https://backpack.tf/profiles/76561198145748582#!/compare/1583539200/1583884800

https://backpack.tf/profiles/76561198391320101#!/compare/1582070400/1583971200

https://backpack.tf/profiles/76561198391320101#!/compare/1583971200/1584057600

https://backpack.tf/profiles/76561197963335915#!/compare/1582934400/1584057600

https://backpack.tf/profiles/76561198020673987#!/compare/1584144000/1584489600

https://backpack.tf/profiles/76561198850274253#!/compare/1584489600/1584489600/nearest

Untrace / bulk

Resuggesting with a slightly larger range!