Sale 1:

https://backpack.tf/profiles/76561198100477765#!/compare/1565913600/1566000000

https://backpack.tf/profiles/76561198841279602#!/compare/1565913600/1566000000

QS

sale 2:

https://backpack.tf/profiles/76561198869422682#!/compare/1565913600/1566000000

https://backpack.tf/profiles/76561198084937685#!/compare/1565913600/1566000000

Bulky

Sale 3:

https://backpack.tf/profiles/76561198084937685#!/compare/1566172800/1566259200

https://backpack.tf/profiles/76561198275390406#!/compare/1566172800/1566259200

Sold for 9 keys

sale 4:

https://backpack.tf/profiles/76561198275390406#!/compare/1566345600/1566432000

https://backpack.tf/profiles/76561198006432645#!/compare/1566345600/1566432000

Sold for at least 4 keys, Oiled seems to be the other part but doesn't match?

Sale 5:

https://backpack.tf/profiles/76561198006432645#!/compare/1566345600/1566432000

https://backpack.tf/profiles/76561198124241068#!/compare/1566345600/1566432000

Sold for DP Combustible + ~1 key in sweets

Combust Mini:

https://backpack.tf/suggestion/5dce5ba6d3817201de7b1340

Suggestion for 8.25 keys

Total is 9.25 keys

sale 6:

https://backpack.tf/profiles/76561198124241068#!/compare/1566432000/1566518400

https://backpack.tf/profiles/76561198883085944#!/compare/1566518400/1566950400

Untrace

sale 7:

https://backpack.tf/profiles/76561198050024400#!/compare/1567209600/1568592000

https://backpack.tf/profiles/76561198106409123#!/compare/1567209600/1567382400

Untrace

Sale 8:

https://backpack.tf/profiles/76561198106409123#!/compare/1568851200/1569110400

https://backpack.tf/profiles/76561198856392285#!/compare/1569024000/1569110400

Sold for keys or cap

Sale 9:

https://backpack.tf/profiles/76561198856392285#!/compare/1569110400/1569196800

https://backpack.tf/profiles/76561198363070402#!/compare/1569024000/1569196800

https://backpack.tf/profiles/76561198363070402#!/compare/1569283200/1569542400

https://backpack.tf/profiles/76561198856392285#!/compare/1569196800/1569715200

Tradeback

Sale 10:

https://backpack.tf/profiles/76561198856392285#!/compare/1571788800/1571961600

https://backpack.tf/profiles/76561198044684270#!/compare/1571788800/1571875200

QS

sale 11:

https://backpack.tf/profiles/76561198080179568#!/compare/1567382400/1567468800

https://backpack.tf/profiles/76561198211831923#!/compare/1561939200/1569110400

Sold for 11 keys

sale 12:

https://backpack.tf/profiles/76561198211831923#!/compare/1569110400/1573689600

https://backpack.tf/profiles/76561198392153699#!/compare/1573171200/1573430400

Untrace

sale 13:

https://backpack.tf/profiles/76561198306912450#!/compare/1570665600/1571443200

https://backpack.tf/profiles/76561198122085087#!/compare/1570492800/1570752000

Sold for spell

Sale 14:

https://backpack.tf/profiles/76561198153655029#!/compare/1565308800/1566000000

https://backpack.tf/profiles/76561198271772640#!/compare/1565913600/1566000000

SCM

sale 15:

https://backpack.tf/profiles/76561198271772640#!/compare/1566432000/1566604800

https://backpack.tf/profiles/76561198280637226#!/compare/1566432000/1566604800

Sold for Stormy Western + 2 keys

use there

Sale 16:

https://backpack.tf/profiles/76561198280637226#!/compare/1566604800/1566691200

https://backpack.tf/profiles/76561198065400580#!/compare/1566518400/1566691200

Sold with ~2 keys for P Fetti Swagman

use there

sale 17:

https://backpack.tf/profiles/76561198065400580#!/compare/1566691200/1566777600

https://backpack.tf/profiles/76561198082377587#!/compare/1566518400/1566777600

Sold for Aces Wet Works(9) + MW Party Trick(2.75)

Total is 11.75 keys

https://bot.tf/stats/listings/4PP9LRPZ

B/O of 13 keys

sale 18:

https://backpack.tf/profiles/76561198082377587#!/compare/1566777600/1566864000

https://backpack.tf/profiles/76561198341454324#!/compare/1566864000/1566950400

Sold for TW Milkman(12.5) + ~0.49 keys in sweets

Total is ~13 keys

Sale 19:

https://backpack.tf/profiles/76561198341454324#!/compare/1566864000/1566950400

https://backpack.tf/profiles/76561198363149044#!/compare/1566777600/1566950400

Sold for DBD HWAH + 2 keys

HWAH Mini:

https://backpack.tf/suggestion/5dce1f5e678072764a2695b9

Suggestion for 9.75 keys

Total is 11.75 keys

Sale 20:

https://backpack.tf/profiles/76561198363149044#!/compare/1567382400/1567555200

https://backpack.tf/profiles/76561198342161127#!/compare/1567468800/1567555200

Bulky / QS

sale 21:

https://backpack.tf/profiles/76561198123546775#!/compare/1566086400/1566259200

https://backpack.tf/profiles/76561198930959573#!/compare/1568764800/1568764800

Untrace

Sale 22:

https://backpack.tf/profiles/76561198198164517#!/compare/1568419200/1573689600

https://backpack.tf/profiles/76561198200973421#!/compare/1569888000/1570147200

Untrace

Sale 23:

https://backpack.tf/profiles/76561198930959573#!/compare/1568764800/1568764800

https://backpack.tf/profiles/76561198251658086#!/compare/1555718400/1572825600

Untrace

sale 24:

https://backpack.tf/profiles/76561198361663051#!/compare/1567900800/1568160000

https://backpack.tf/profiles/76561198024867201#!/compare/1568073600/1568160000

Sold for ~6.5 keys (QS)

sale 25:

https://backpack.tf/profiles/76561198024867201#!/compare/1573084800/1573171200

https://backpack.tf/profiles/76561198943080662#!/compare/1572998400/1573257600

Keys

sale 26:

https://backpack.tf/profiles/76561198268640581#!/compare/1566000000/1566345600

https://backpack.tf/profiles/76561198300039170#!/compare/1565481600/1566000000

SCM

sale 27:

https://backpack.tf/profiles/76561198300039170#!/compare/1566604800/1566691200

https://backpack.tf/profiles/76561198329102247#!/compare/1560816000/1566604800

Untrace

sale 28:

https://backpack.tf/profiles/76561198329102247#!/compare/1567209600/1568937600

https://backpack.tf/profiles/76561198300039170#!/compare/1567468800/1568332800

Transfer

Sale 29, 30:

https://marketplace.tf/items/tf2/109;5;u61

$19.99 / $1.84 = 10.86 keys <--- https://backpack.tf/item/7955758646

$19.99 / $1.83 = 10.92 keys <--- https://backpack.tf/item/7956830272

Total sales @:

9, 9.25 10.86, 10.92, 11 11.75, 11.75, 13 keys

buyers up to ~7 keys,

sellers down to 13 keys,

considering long unsold at 13,

and 13 resold for lower,

taking 9 - 12 keys.