Counterpart suggestion to this: http://backpack.tf/vote/id/552d4de0b88d88135a8b4b48

Very small market for these things.

Sold

http://www.tf2outpost.com/trade/25655914 - They mention in the comments they are selling all the crests for 1 key each. I contacted the seller since I was interested in the plain crest, and was offered a deal of all 3 crests for 2 keys, hence the range: http://i.imgur.com/4r0U6QN.png and http://i.imgur.com/0lUgf32.png

Sellers

Only other seller is in the classifieds for 1 key: http://i.imgur.com/Fvrjk1f.png

Buyers

http://www.tf2outpost.com/trade/25662516 - 1 ref

http://www.tf2outpost.com/trade/25635667 - 3 ref (current bp.tf price)

Other

http://www.tf2outpost.com/trade/25298269 - A buy/sell bot, lists that it is buying for 2.22 ref and selling for 3 ref (bp.tf price) but it has no crests in its inventory nor any evidence it has purchased or sold a Copper Crest.