Proof that it sells for this?

That's not how it works, you need solid proof. This isn't an expensive item because you can get other, less valuable versions of it, which you can't with most other high-value items (buds, BMOC, Max's, etc). The fact you can get a Unique one for about 3 keys means that this is not a sign of wealth, which the other items I mentioned are. Whilst it SHOULD be higher, it's not. Find proof that it sells for 19 keys. You also have one in your BP. So... downvote.

http://www.tf2outpost.com/trade/6746176 - 18 keys

http://www.tf2outpost.com/trade/6735222 - 18 keys

http://www.tf2outpost.com/trade/6759191 - 18 keys

http://www.tf2outpost.com/trade/6688401 - 17.5 keys

http://www.tf2outpost.com/trade/6688064 - 18 keys

http://www.tf2outpost.com/trade/6638863 - 18 keys

d-d-d-d-downvote