Sale #1:

https://backpack.tf/profiles/76561198339225343#!/compare/1545868800/1545955200

Untracable.

----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Sale #2:

https://marketplace.tf/items/30917;5;u3019

Sold for $7.50.

$7.50 / $1.79 = ~4 keys

4 keys

----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Sale #3:

https://marketplace.tf/items/30917;5;u3019

Sold for $9.11.

$9.11 / $1.78 = ~5 keys

5 keys

----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Sale #4:

https://marketplace.tf/items/30917;5;u3019

Sold for $7.52.

$7.52 / $1.79 = ~4 keys

4 keys

Sales:

4, 4, 5. Going with 4 - 5 keys.