Classifieds at the time of posting this suggestion.

Unsolds are based on how long the listing has been up; Listing has been up 5 days and item been in the sellers inventory for 8 days? It has been unsold for 5 days.

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 19.66 Refined(20 Charges) - http://i.imgur.com/8jhdqzj.png

Unsold for 1 day http://backpack.tf/item/520326286

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x2 for sale at 1 Key(25 Charges) - http://i.imgur.com/8l3rYyo.png

Unsold for 1 day http://backpack.tf/item/519023400

Unsold for 4 days http://backpack.tf/item/1874644048

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x4 for sale at 1.1 Keys(x1 23 Charges, x3 25 Charges, all 4 same seller) - http://i.imgur.com/sA1hZIi.png

Unsold for 6 days http://backpack.tf/item/837331180

Unsold for 6 days http://backpack.tf/item/643972021

Unsold for 6 days http://backpack.tf/item/756959488

Unsold for 6 days http://backpack.tf/item/522847106

Outpost sellers.

http://www.tf2outpost.com/trade/28440877 - 1 Key, 25 Charges - Unsold for 1 day - Autobumper.

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http://www.tf2outpost.com/trade/28123840 - 1.5 Keys, 25 Charges - Unsold for 3 months.

Including this one as this person has sold 1, 3 months ago. So it's not valid, pointing that out here.

Suggesting 1 Key instead of 19.66 Refined as the seller at 19.66 Refined is selling one with 20 Charges.