2 in the world, but only could find 1 of them. Sold once for 2.2 pure, was offered 2.3 buds after unusual overpay.

http://www.tf2outpost.com/trade/11579629

Had an offer of a Stormy Bubble Pipe + 5 keys (2.4-2.7) ~ 2.3 buds pure

Sold it with 2 buds and a TS Bills for a Anti-Freeze Robo-Glove (currently unpriced)

http://www.tf2outpost.com/trade/11572724 http://www.tf2outpost.com/user/83296

Sold for 1 bud + 1 Black Bills + 1 White Bills + 1 TS Bills + SF Buff Banner ~ (2.3 buds) ~ 2.2 buds pure

Note the items I mentioned were all owned by Op@lice prior to Ye Ol' Buttchecks.

New evidence has appears that significantly changes the value of this offer. My apologize to those that voted. I will have a new, more accurate suggestion up shortly.