Sale 1:

https://backpack.tf/profiles/76561198076175118#!/compare/1588204800/1588723200

https://backpack.tf/profiles/76561197967470975#!/compare/1588118400/1588982400

Untrace

Sale 2:

https://backpack.tf/profiles/76561198839259306#!/compare/1590451200/1590624000

https://backpack.tf/profiles/76561198951163629#!/compare/1590624000/1590710400

Sold with 1 key for Aussie Axe(~7)

Total is 6 keys

sale 3:

https://backpack.tf/profiles/76561198951163629#!/compare/1591488000/1592265600

https://backpack.tf/profiles/76561198223881088#!/compare/1591574400/1591920000

Sold for ~5.5 keys

sale 4:

https://backpack.tf/profiles/76561198223881088#!/compare/1592524800/1592611200

https://backpack.tf/profiles/76561198068732040#!/compare/1592524800/1592611200

Bulk

sale 5:

https://backpack.tf/profiles/76561198136200017#!/compare/1587081600/1588809600

https://backpack.tf/profiles/76561198091929681#!/compare/1552780800/1587168000

https://backpack.tf/profiles/76561198136200017#!/compare/1587081600/1588809600

Tradeback

sale 6:

https://backpack.tf/profiles/76561198136200017#!/compare/1589500800/1589587200

https://backpack.tf/profiles/76561198114402400#!/compare/1589414400/1589500800

Bulk

sale 7:

https://backpack.tf/profiles/76561198317895216#!/compare/1590019200/1590796800

https://backpack.tf/profiles/76561198059439040#!/compare/1591142400/1591574400

SCM

sale 8:

https://marketplace.tf/items/tf2/1015;5;u3031

$11.76 / $1.69 = 6.96 keys

$11.88 / $1.71 = 6.95 keys

$6.6 / $1.89 = 3.49 keys

$11.7 / $1.89 = 6.19 keys

$12 / $1.98 = 6.06 keys <--- https://backpack.tf/item/2178859467

$12 / $1.98 = 6.06 keys <--- https://backpack.tf/item/8375488462

$12 / $1.98 = 6.06 keys

Total sales @:

3.5, 5.5, 6, 6, 6, 6, 6, 7, 7 keys

buyers up to ~4.5 keys,

sellers at 10 keys,

taking 5.5 - 7 keys.