Sale 1:

https://backpack.tf/profiles/76561198067741299#!/compare/1547856000/1547942400

https://backpack.tf/profiles/76561198258264645#!/compare/1547856000/1547942400

Bulk

Sale 2:

https://backpack.tf/profiles/76561198090700029#!/compare/1541635200/1541721600

https://backpack.tf/profiles/76561198833467557#!/compare/1541635200/1541721600

Untrace

Sale 3:

https://backpack.tf/profiles/76561198835318184#!/compare/1542758400/1542931200

https://backpack.tf/profiles/76561198050509345#!/compare/1542931200/1543276800

Keys, can't tell how many.

Sale 4:

https://backpack.tf/profiles/76561198050509345#!/compare/1546732800/1546819200

https://backpack.tf/profiles/76561197993708178#!/compare/1546732800/1546819200

Bulk

Sale 5:

https://backpack.tf/profiles/76561197993708178#!/compare/1547164800/1547337600

https://backpack.tf/profiles/76561198041108750#!/compare/1547251200/1547337600

Sold for ~30 keys

Sale 6:

https://backpack.tf/profiles/76561198369352441#!/compare/1546905600/1547683200

https://backpack.tf/profiles/76561198134234061#!/compare/1547683200/1547769600

Sold for D@D Halogen

Halogen Mini:

https://backpack.tf/suggestion/5c4e025344325a381935c4f5

Suggestion for 30 keys

Sale 7:

https://marketplace.tf/items/104;5;u9

Sold for 69.99 USD

Keys at 1.79 USD

Total is 39.10 keys

DUPED SALES:

Sale 8:

https://backpack.tf/profiles/76561198394877897#!/compare/1548288000/1548374400

https://backpack.tf/profiles/76561198331958859#!/compare/1541289600/1548374400

Sold for 29 keys

Sale 9:

https://backpack.tf/profiles/76561198070281440#!/compare/1547164800/1547251200

QS for 26 keys

Sale 10:

https://backpack.tf/profiles/76561198031448782#!/compare/1545264000/1545609600

Sold for 31 keys

Looks like dupe doesn't sell very differently from clean.

Total sales @:

26, 29, 30, 30, 31, 39 keys

Sellers at 30,

Buyers up to 26 keys,

Taking 29 - 30 keys.