Sale 1:

https://marketplace.tf/items/tf2/30984;5;u7

$16.00 / $1.81 = 8.84 keys

Sale 2:

SCM

https://backpack.tf/profiles/76561198263129464#!/compare/1560988800/1561248000

Sale 3:

untrace

https://backpack.tf/profiles/76561198211794784#!/compare/1550102400/1564876800

Sale 4:

SCM

https://backpack.tf/profiles/76561198424002851#!/compare/1559347200/1559692800

https://backpack.tf/profiles/76561198846521706#!/compare/1558742400/1558828800

Sale 5:

using on Puffy Polar

https://backpack.tf/profiles/76561198113899098#!/compare/1560384000/1560470400

https://backpack.tf/profiles/76561198424002851#!/compare/1560297600/1560384000

Sale 6:

using there

Miami Nights Gridiron Guardian

https://backpack.tf/profiles/76561198113899098#!/compare/1562976000/1563062400

https://backpack.tf/profiles/76561198124887048#!/compare/1563062400/1563148800

Sale 7:

7 keys + 14 ref

https://backpack.tf/profiles/76561198124887048#!/compare/1563062400/1563148800

https://backpack.tf/profiles/76561198363395191#!/compare/1563062400/1563148800

Sale 8:

untrace

https://backpack.tf/profiles/76561198883188648#!/compare/1560816000/1560902400

Sale 9:

untrace

https://backpack.tf/profiles/76561198883188648#!/compare/1560902400/1560988800

Sale 10:

Bulk for pile of crap

https://backpack.tf/profiles/76561198000326258#!/compare/1558742400/1558828800

https://backpack.tf/profiles/76561198452496286#!/compare/1558742400/1558828800

Sale 11:

sold with 19 ref for 8 keys

https://backpack.tf/profiles/76561198452496286#!/compare/1558742400/1558828800

https://backpack.tf/profiles/76561198379996789#!/compare/1558742400/1558828800

Sale 12:

untrace

https://backpack.tf/profiles/76561198140083209#!/compare/1560470400/1560556800

Sale 13:

untrace

https://backpack.tf/profiles/76561198140083209#!/compare/1560556800/1560643200

Sale 14:

7 keys + 2 scrap

https://backpack.tf/profiles/76561198048851745#!/compare/1560556800/1560643200

https://backpack.tf/profiles/76561198140507799#!/compare/1560556800/1560643200

Sale 15:

7 keys + 17 ref

https://backpack.tf/profiles/76561198048851745#!/compare/1562716800/1562803200

https://backpack.tf/profiles/76561198132002939#!/compare/1562544000/1562716800

Sale 16:

untrace

https://backpack.tf/profiles/76561198132002939#!/compare/1562716800/1562803200

https://backpack.tf/profiles/76561198841279602#!/compare/1562716800/1562803200

Sale 17:

untrace

https://backpack.tf/profiles/76561198841279602#!/compare/1563062400/1563148800

https://backpack.tf/profiles/76561198185368990#!/compare/1563062400/1563235200

Sale 18:

Bulk

https://backpack.tf/profiles/76561198061440669#!/compare/1563321600/1563408000

https://backpack.tf/profiles/76561198185368990#!/compare/1563235200/1563408000

==============================================================================

Sales:

7, 7, 7.5, 7.5, 9

Buyers at 7 keys: https://imgur.com/a/02F2fFu

Unsold at 8 for nearly 2 months:

https://imgur.com/a/z2YvGOC

https://imgur.com/a/8Ein8ar