Resuggestion, thank to Crimson and Mindacos for the info!

Maybe aliens haven't visited yet because they looked up reviews on our solar system and only saw 1 star.

Sale 1:

https://backpack.tf/profiles/76561198357865695#!/compare/1570147200/1570320000

https://backpack.tf/profiles/76561198832639251#!/compare/1570233600/1570320000

Sold for 20 keys

sale 2:

https://backpack.tf/profiles/76561198832639251#!/compare/1570492800/1570579200

https://backpack.tf/profiles/76561198095022965#!/compare/1570492800/1570579200

Sold for 25 keys

Sale 3:

https://backpack.tf/profiles/76561198095022965#!/compare/1571184000/1571270400

https://backpack.tf/profiles/76561198064374638#!/compare/1571011200/1571270400

Bulk

sale 4:

https://backpack.tf/profiles/76561198064374638#!/compare/1571270400/1571443200

https://backpack.tf/profiles/76561198012613726#!/compare/1571356800/1571529600

Sold with ~1 key in sweets for HG Chieftain

use there

sale 5:

https://backpack.tf/profiles/76561198076113077#!/compare/1569196800/1569369600

https://backpack.tf/profiles/76561198052694464#!/compare/1569283200/1569369600

Bulk

sale 6:

https://backpack.tf/profiles/76561198052694464#!/compare/1569369600/1569456000

https://backpack.tf/profiles/76561198044872043#!/compare/1559606400/1569456000

Bulky

sale 7:

https://backpack.tf/profiles/76561198044872043#!/compare/1569888000/1569974400

https://backpack.tf/profiles/76561198419584303#!/compare/1569888000/1569974400

Sold for TW KE

KE Mini:

https://backpack.tf/suggestion/5dd88e82678072278b088799

suggestion for 27.5 keys

Sale 8:

https://backpack.tf/profiles/76561198419584303#!/compare/1569888000/1569974400

https://backpack.tf/profiles/76561198039731024#!/compare/1569888000/1569974400

https://backpack.tf/profiles/76561198831596900#!/compare/1569888000/1569974400

Untrace / bulk

Sale 9:

https://backpack.tf/profiles/76561198831596900#!/compare/1569974400/1570060800

https://backpack.tf/profiles/76561198141405429#!/compare/1569974400/1570060800

Bulk

Sale 10:

https://backpack.tf/profiles/76561198141405429#!/compare/1570060800/1570147200

https://backpack.tf/profiles/76561198037674114#!/compare/1567209600/1570147200

Bulk

Total sales @:

20, 25, 27.5 keys

Crimson's Part:

25 sold in an hour: https://i.imgur.com/9QsqbW2.gifv

Mindacos' Part:

Looking at the histories, this seems to add up. I guess if 25 is a quicksell, this should be resuggested at 28 flat.