Sale 1:

https://backpack.tf/profiles/76561198232646232#!/compare/1566950400/1567036800

https://backpack.tf/profiles/76561198219776568#!/compare/1566691200/1567123200

Bulky

sale 2:

https://backpack.tf/profiles/76561198080179568#!/compare/1570406400/1570492800

https://backpack.tf/profiles/76561198095545950#!/compare/1570406400/1570492800

Sold for 7 keys

sale 3:

https://backpack.tf/profiles/76561198095545950#!/compare/1570579200/1570665600

https://backpack.tf/profiles/76561198394963563#!/compare/1570579200/1570665600

Sold for ~7 keys in sweets

Sale 4:

https://backpack.tf/profiles/76561198394963563#!/compare/1570665600/1570924800

https://backpack.tf/profiles/76561198334289235#!/compare/1570838400/1570924800

Sold for keys

sale 5:

https://backpack.tf/profiles/76561198334289235#!/compare/1570924800/1573430400

https://backpack.tf/profiles/76561198323565601#!/compare/1570838400/1570924800

QS

Sale 6:

https://backpack.tf/profiles/76561198334116863#!/compare/1566691200/1566864000

https://backpack.tf/profiles/76561198868895391#!/compare/1565654400/1566864000

Untrace

sale 7:

https://backpack.tf/profiles/76561198868895391#!/compare/1566864000/1566950400

https://backpack.tf/profiles/76561198323565601#!/compare/1566777600/1566864000

Untrace

Sale 8:

https://backpack.tf/profiles/76561198285371555#!/compare/1565913600/1566000000

https://backpack.tf/profiles/76561198329662739#!/compare/1565913600/1566000000

Sold for 6 keys

sale 9:

https://backpack.tf/profiles/76561198329662739#!/compare/1565913600/1566000000

https://backpack.tf/profiles/76561198116559834#!/compare/1565913600/1566000000

Untrace

Sale 10:

https://backpack.tf/profiles/76561198116559834#!/compare/1566000000/1566086400

https://backpack.tf/profiles/76561198877975149#!/compare/1566000000/1566086400

Untrace

Sale 11:

https://backpack.tf/profiles/76561198877975149#!/compare/1566000000/1566086400

https://backpack.tf/profiles/76561198440092405#!/compare/1565308800/1566086400

Sold for DP Soviet

use there

sale 12:

https://backpack.tf/profiles/76561198440092405#!/compare/1566086400/1573430400

https://backpack.tf/profiles/76561198441172305#!/compare/1566172800/1566259200

Untrace

sale 13:

https://backpack.tf/profiles/76561198441172305#!/compare/1566259200/1566432000

https://backpack.tf/profiles/76561198119563409#!/compare/1566345600/1566432000

Sold for 6 keys (QS)

Sale 14:

https://backpack.tf/profiles/76561198119563409#!/compare/1566518400/1566604800

https://backpack.tf/profiles/76561198332344457#!/compare/1566518400/1566604800

Sold for 7 keys

sale 15:

https://backpack.tf/profiles/76561198332344457#!/compare/1566604800/1566691200

https://backpack.tf/profiles/76561198858663191#!/compare/1566604800/1566691200

Sold for ~7 keys (one key in bunch of 8 does not match)

sale 16:

https://backpack.tf/profiles/76561198858663191#!/compare/1566604800/1566691200

https://backpack.tf/profiles/76561198046393528#!/compare/1566604800/1566691200

Untrace

sale 17:

https://backpack.tf/profiles/76561198046393528#!/compare/1566864000/1566950400

https://backpack.tf/profiles/76561198838120808#!/compare/1566950400/1566950400/nearest

https://backpack.tf/profiles/76561198069967202#!/compare/1566864000/1566950400

Untrace

sale 18, 19:

https://marketplace.tf/items/tf2/721;5;u60

$13.78 / $1.80 = 7.66 keys <--- https://backpack.tf/item/3569120301

$13.2 / $1.77 = 7.46 keys

Total sales @:

6, 6, 7, 7, 7, 7, 7.46, 7.66 keys

buyers up to ~5.5 keys,

sellers at ~8.5 keys.

lets call 6 low,

7.5 high,

taking 7 flat.