Sale 1:

https://backpack.tf/profiles/76561198080179568#!/compare/1569110400/1569196800

https://backpack.tf/profiles/76561198216982180#!/compare/1569110400/1569196800

Sold for 12 keys (one key came from ref to key bot)

Sale 2:

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

https://backpack.tf/profiles/76561198071588645#!/compare/1570406400/1570492800

Sold for 13 keys

sale 3:

https://backpack.tf/profiles/76561198071588645#!/compare/1570492800/1570752000

https://backpack.tf/profiles/76561198086368143#!/compare/1568764800/1570752000

Bulky

sale 4:

https://backpack.tf/profiles/76561198095514968#!/compare/1568160000/1568246400

https://backpack.tf/profiles/76561198021055079#!/compare/1568160000/1568246400

Sold for 11 keys

sale 5:

https://backpack.tf/profiles/76561198152370674#!/compare/1567036800/1567123200

https://backpack.tf/profiles/76561198363395191#!/compare/1567036800/1567123200

QS

sale 6:

https://backpack.tf/profiles/76561198363395191#!/compare/1568764800/1568851200

https://backpack.tf/profiles/76561198089253101#!/compare/1568764800/1568851200

https://backpack.tf/profiles/76561198205939253#!/compare/1568764800/1568851200

untrace

sale 7:

https://backpack.tf/profiles/76561198059215872#!/compare/1566172800/1566691200

https://backpack.tf/profiles/76561198097271466#!/compare/1566604800/1566691200

Sold for 12 keys (QS)

sale 8:

https://backpack.tf/profiles/76561198097271466#!/compare/1570233600/1570320000

https://backpack.tf/profiles/76561198028340642#!/compare/1570060800/1570406400

Sold for ~12 keys

sale 9:

https://backpack.tf/profiles/76561198015834883#!/compare/1572220800/1572825600

https://backpack.tf/profiles/76561198080179568#!/compare/1572739200/1572825600

QS

Sale 10:

https://backpack.tf/profiles/76561198342263310#!/compare/1570147200/1571875200

https://backpack.tf/profiles/76561198994027328#!/compare/1571097600/1571961600

https://backpack.tf/profiles/76561198097271466#!/compare/1571011200/1571097600

Untrace

sale 11!:

https://backpack.tf/profiles/76561198097271466#!/compare/1571270400/1571356800

https://backpack.tf/profiles/76561198058374066#!/compare/1571270400/1571616000

keys

sale 12:

https://backpack.tf/profiles/76561198058374066#!/compare/1572912000/1573084800

https://backpack.tf/profiles/76561198117390056#!/compare/1572912000/1572998400

Untrace

sale 13:

https://backpack.tf/profiles/76561198117390056#!/compare/1573084800/1573171200

https://backpack.tf/profiles/76561198220098345#!/compare/1572998400/1573171200

Untrace

Sale 14:

https://backpack.tf/profiles/76561198220098345#!/compare/1573171200/1573257600

https://backpack.tf/profiles/76561197972404012#!/compare/1573084800/1573257600

Sold for ~11 keys

sale 15:

https://backpack.tf/profiles/76561197972404012#!/compare/1573257600/1573603200

https://backpack.tf/profiles/76561197994697258#!/compare/1573516800/1573603200

Bulk

Sale 16, 17:

https://marketplace.tf/items/tf2/30116;5;u62

$27.5 / $1.81 = 15.19 keys

$27.5 / $1.78 = 15.45 keys

Total sales @:

11, 11, 12, 12, 12, 13, 15, 15 keys

buyers up to 11 keys,

sellers at 16 keys,

calling 2 outliers on either side,

taking 12 - 13 keys.