Resuggesting

credits to Foamy for his feedback in the previous suggestion

sale 1: 35 keys (QS)

https://backpack.tf/profiles/76561198041228333#!/compare/1523145600/1523232000

sale 2: bulk

https://backpack.tf/profiles/76561198334367671#!/compare/1523145600/1523232000

sale 3: Clean Strange Sunbeams Private Eye + 2 pure

https://backpack.tf/profiles/76561198334367671#!/compare/1523750400/1523836800

mini for private

https://marketplace.tf/shopitem/m9s/388;5;u17;strange/Strange%20Sunbeams%20Private%20Eye

sold for $119.86

119.86/1.96= ~61 keys

Rounding sale down to 60 due to sellers 58-60 on the private eye

sale 4: Sold w/ 21 pure for clean DBD modest

https://backpack.tf/profiles/76561198129205357#!/compare/1525046400/1525132800

Mini for modest: $140

https://marketplace.tf/items/139;5;u62

$140 / $1.95 = ~72 keys

72 - 21 = 51 keys

Rounding down to 50

Taking 50 keys

sale 5: untraceable

https://backpack.tf/profiles/76561198048563101#!/compare/1525305600/1525392000

https://backpack.tf/profiles/76561198065409820#!/compare/1525305600/1525392000

sale 6: Strange Specialized Killstreak Australium Rocket Launcher (33k) (QS)

https://backpack.tf/profiles/76561198093926010#!/compare/1526601600/1526688000

sale 6: 40k (QS)

https://backpack.tf/profiles/76561197963394917#!/compare/1527120000/1527206400

sale 7: Sold w/ 4k for clean Blizz Storm Neckwear Headwear

https://backpack.tf/profiles/76561198084682544#!/compare/1527206400/1527292800

mini for neckwear

https://backpack.tf/profiles/76561198065157321#!/compare/1528416000/1528502400

Sold w/ 1 pure for Blizz Storm Salty Dog

Micro for Salty

https://marketplace.tf/shopitem/waadebp/611;5;u30

Sold for $78

78 / 1.96 = 39.8 rounding to 40

Taking 35 for sale

Sale 8: bulk

https://backpack.tf/profiles/76561198272881838#!/compare/1527465600/1527552000

https://backpack.tf/profiles/76561198089253101#!/compare/1527465600/1527552000

Sale 9: Anti Freeze Coupe + 6 keys + 30 ref (~1 key)

https://backpack.tf/profiles/76561198272881838#!/compare/1527724800/1527811200

mini for coupe

https://backpack.tf/suggestion/5b02f5f8cf6c75631167dd71

Taking 59 keys for the sale

rounding to 60 for better number

Sale 10: Sold w/ 3 pure for DBD Caribou (56)

https://backpack.tf/profiles/76561198119149660#!/compare/1529107200/1529193600

Rounding the sale to 55

Sale 11: Duped Sunbeams Noir

https://backpack.tf/profiles/76561198251704884#!/compare/1529107200/1529193600

Mini for noir: essentially ~52 pure

https://backpack.tf/profiles/76561198179707937#!/compare/1530230400/1530316800

Taking 52

Valid sales are 50, 52, 60, and 60

Taking range 50-60

Seller at 55 for ~1 month supports this price and sale @ 52 supports range