Mini for a requested suggestion.

Sale #1 - Untrace / Bulk

https://backpack.tf/profiles/76561198121280601#!/compare/1567036800/1568419200

https://backpack.tf/profiles/76561198156255538#!/compare/1568505600/1568678400

Sale #2 - Untrace

https://backpack.tf/profiles/76561198199217834#!/compare/1567123200/1567209600

https://backpack.tf/profiles/76561198342161127#!/compare/1567123200/1567209600

Sale #3 - 24 keys

https://backpack.tf/profiles/76561198333986358#!/compare/1566518400/1566604800

https://backpack.tf/profiles/76561198830092977#!/compare/1566518400/1566604800

Sale #4 - CHeart Polar + Grain Square (Use on the polar to give it a range.)

https://backpack.tf/profiles/76561198185059557#!/compare/1566000000/1566086400

https://backpack.tf/profiles/76561198017954131#!/compare/1566000000/1566086400

Taking ? + ?

b/o was 26 - https://bot.tf/stats/listings/4KR0GVD0

Sale #5 - Bulk

https://backpack.tf/profiles/76561198017954131#!/compare/1569888000/1570060800

https://backpack.tf/profiles/76561198168863803#!/compare/1569974400/1570060800

Sale #6 -

https://marketplace.tf/items/tf2/30827;5;u17 | https://backpack.tf/item/5375209925 | Cant find a b/o

$46.99 / $1.83 = 25.68 keys

Sale #7 - Untrace

https://backpack.tf/profiles/76561198290033158#!/compare/1572393600/1573257600

https://backpack.tf/profiles/76561198002757046#!/compare/1573171200/1573257600

Sale #8, 9, 10 - https://marketplace.tf/items/tf2/30827;5;u17

Cant find a history / b/o on them

$32.99 / $1.81 = 18.23 keys

$47.99 / $1.81 = 26.51 keys

$20 / $1.79 = 11.17 keys

Sale #11 - 21 keys 11 ref

https://backpack.tf/profiles/76561198867206652#!/compare/1570665600/1570924800

https://backpack.tf/profiles/76561198327078449#!/compare/1570838400/1570924800

Sale #12 - Bulk

https://backpack.tf/profiles/76561198305246292#!/compare/1571788800/1571875200

https://backpack.tf/profiles/76561197994697258#!/compare/1571702400/1571788800

Sale #13 - 14 keys 2 ref

https://backpack.tf/profiles/76561198041186431#!/compare/1570579200/1570665600

https://backpack.tf/profiles/76561198314211872#!/compare/1570579200/1570665600

Sale #14 - Untrace

https://backpack.tf/profiles/76561198314211872#!/compare/1570924800/1571011200

https://backpack.tf/profiles/76561198833954279#!/compare/1571184000/1571356800

Sale #15 - Bulk

https://backpack.tf/profiles/76561198192602363#!/compare/1571356800/1571443200

https://backpack.tf/profiles/76561198833954279#!/compare/1571356800/1571443200

Sale #16 - 23 keys

https://backpack.tf/profiles/76561198192602363#!/compare/1571961600/1572048000

https://backpack.tf/profiles/76561198083482001#!/compare/1571443200/1572134400

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Taking 18 - 23