sellers (only one)

http://www.tf2outpost.com/trade/27383302 10 keys

buyers and sold

http://www.tf2outpost.com/trade/27376903 sold @ 2.5 keys

These are rare and expired; thus, sales are limited.

Because they are a usable item they are consumed immediately upon the trade, thus they are not traceable. In addition, most are held on alts, so they will not be seen in the traders bp.

The items traded for are also not traceable as the traded items are also placed in the unknown alts bp.

a few other sellers taking offers, not responding to trades, or refusing to sell at their own asking price.

disclaimer = I own some