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 17 Refined - http://i.imgur.com/GpbGw2I.png

Unsold for 4 hours(Gold paint) http://backpack.tf/item/4992512773

-

x2 for sale at 18 Refined - http://i.imgur.com/kAUTAJ0.png

Unsold for 6 days http://backpack.tf/item/4747819472

Unsold for 6 days http://backpack.tf/item/4911233240

-

x1 for sale at 19 Refined - http://i.imgur.com/KW6DFhC.png

Unsold for 2 days(Parts Attached) http://backpack.tf/item/4247083576

-

x4 for sale at 1 Key - http://i.imgur.com/HShGqlW.png

Unsold for 6 days http://backpack.tf/item/5019801024

Unsold for 12 days http://backpack.tf/item/4192159992

Unsold for 2 days http://backpack.tf/item/5056402142

Unsold for 3 days http://backpack.tf/item/5037040923

Suggesting 18 Refined due to how young the 17 Refined listing is.