Sale 1:

https://backpack.tf/profiles/76561198092621591#!/compare/1564963200/1565136000

https://backpack.tf/profiles/76561198929490008#!/compare/1562025600/1565308800

Untrace

sale 2:

https://backpack.tf/profiles/76561198101092551#!/compare/1572048000/1572134400

https://backpack.tf/profiles/76561198866452747#!/compare/1571616000/1572134400

Sold for Enchanted Bronco

use there

Sale 3:

https://backpack.tf/profiles/76561198124836436#!/compare/1566000000/1568505600

https://backpack.tf/profiles/76561197995376241#!/compare/1565913600/1566000000

Untrace

sale 4:

https://backpack.tf/profiles/76561198258932668#!/compare/1566000000/1566086400

https://backpack.tf/profiles/76561198337982050#!/compare/1566000000/1566086400

Sold for Aces Buckaroo

use there, few sales

Sale 5:

https://backpack.tf/profiles/76561198337982050#!/compare/1566000000/1566086400

https://backpack.tf/profiles/76561198179178805#!/compare/1566000000/1566086400

Sold with ~6 keys in aussies for DBD Geezer

Geezer Mini:

https://backpack.tf/suggestion/5db647046780720159758cea

Suggestion for 14.5 keys

Total is 8.5 keys

Sale 6:

https://backpack.tf/profiles/76561198179178805#!/compare/1566086400/1566172800

https://backpack.tf/profiles/76561198381500437#!/compare/1566086400/1566172800

Sold for spelled Bill's

Sale 7:

https://backpack.tf/profiles/76561198381500437#!/compare/1566086400/1566172800

https://backpack.tf/profiles/76561198043992035#!/compare/1566086400/1566172800

Sold for ~8 keys

Sale 8:

https://marketplace.tf/items/tf2/30406;5;u56

$19 / $1.82 = 10.44 keys

Total sales @:

8, 8.5, 10.44 keys

Taking 8 - 10.5 keys, rounding to 0.5 since average is below 10.