Squad 2, Challenge 15, Team Virtual Item Addicts!

Sale 1:

https://backpack.tf/profiles/76561198030375684#!/compare/1553558400/1553731200

https://backpack.tf/profiles/76561198277449857#!/compare/1553558400/1553731200

Untrace

sale 2:

https://backpack.tf/profiles/76561198178265123#!/compare/1553126400/1553212800

https://backpack.tf/profiles/76561198061836787#!/compare/1553212800/1553385600

Untrace

sale 3:

https://backpack.tf/profiles/76561198146307127#!/compare/1552089600/1552176000

https://backpack.tf/profiles/76561198382290208#!/compare/1552089600/1552176000

Sold for ~7.5 keys

Sale 4:

https://backpack.tf/profiles/76561198382290208#!/compare/1552089600/1552176000

https://backpack.tf/profiles/76561198210225228#!/compare/1552089600/1552176000

https://backpack.tf/profiles/76561198373303727#!/compare/1551657600/1552953600

Untrace

sale 5:

https://backpack.tf/profiles/76561198373303727#!/compare/1552953600/1555200000

https://backpack.tf/profiles/76561198869093037#!/compare/1555200000/1555545600

SCM

Sale 6:

https://backpack.tf/profiles/76561198869093037#!/compare/1555804800/1557446400

https://backpack.tf/profiles/76561198851076456#!/compare/1556668800/1556841600

Sold for DP Strontium

Use there

Sale 7:

https://backpack.tf/profiles/76561198851076456#!/compare/1556668800/1556841600

https://backpack.tf/profiles/76561198080179568#!/compare/1556841600/1557273600

Untrace

Sale 8:

https://backpack.tf/profiles/76561198112099979#!/compare/1557532800/1557619200

https://backpack.tf/profiles/76561198134546405#!/compare/1557532800/1557619200

https://backpack.tf/profiles/76561198363395191#!/compare/1557532800/1557619200

Untrace

Sale 9 - 12:

https://marketplace.tf/items/30911;5;u32

$16.40 / $1.8 = 9.11 keys

$12.04 / $1.8 = 6.69 keys

$16.39 / $1.78 = 9.21 keys

$15.99 / $1.79 = 8.93 keys

Total sales @:

6.69, 7, 8.93, 9.11, 9.21 keys

Buyers up to ~7.5 keys,

Taking 9 keys flat.