Classifieds at the time of posting this suggestion.

The age of the listing(s) are shown in the screenshots rather than the last bump - Unsolds and item histories are presented in chronological order according to the screenshot(s).

x1 for sale at 2.7 Keys - http://i.imgur.com/x2STqcm.png

Unsold for 5 days http://backpack.tf/item/1354491341

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x2 for sale at 2.75 Keys - http://i.imgur.com/zjz4uP3.png

Unsold for 4 days http://backpack.tf/item/1362974793

Unsold for 5 days(Duplicated) http://backpack.tf/item/1359641127

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x2 for sale at 2.8 Keys - http://i.imgur.com/mWOonyS.png

Unsold for 7 days http://backpack.tf/item/1352672917

Unsold for 9 days http://backpack.tf/item/1330352515

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x1 for sale at 3 Keys - http://i.imgur.com/EgXnfJp.png

Unsold for 4 days http://backpack.tf/item/1359904447

Outpost sellers.

http://www.tf2outpost.com/trade/28475880 - 2.8 Keys - Unsold for 2 days - Autobumper.

http://www.tf2outpost.com/trade/28340719 - 3 Keys - Unsold for 1 month - Autobumper.

I am excluding all trades on Outpost that haven't been bumped in 1 day or more.