3 in existence, all 3 were on the market until I bought one. Recently bought it for 10.5 buds:

http://i.imgur.com/gJy6qQk.jpg

http://i.imgur.com/n8HSRIb.jpg

#2 - Was asking for 210 keys, now asking for 180 keys (~12 buds):

http://www.tf2outpost.com/trade/24802958

#3 - Asking for 13 pure (also has Chiroptera Venenata for 12)

http://www.tf2outpost.com/trade/23736059

The trade for one before mine was a 1:1 with a '72 Conga (http://backpack.tf/profiles/76561198037924488?time=1416384000 -> http://backpack.tf/profiles/76561198037924488?time=1416556800) which is currently priced at 10 buds.

The Chiroptera Venenata is essentially a Scorching version of this item, also has 3 in existence, and is priced at 10-12. Think this would be a fair price tag for this unpriced item!