4 months old. Requested on the update forum thread.

Sale:

http://i.imgur.com/JoNqfNb.png?1

SF Bat + 10 keys = ~26-28 keys (SF Bat can easily be QS for 16 keys)

http://www.tf2outpost.com/trade/16805863

QUICK BUYER bought for 18 keys

I searched every hat history that's for sale on outpost, these were the only 2 definitive sales I could find.

Trades & Offers:

http://www.tf2outpost.com/trade/17336834 B/O 25 keys

-17 keys

http://www.tf2outpost.com/trade/17542715 B/O 30 keys

-17 keys

http://www.tf2outpost.com/trade/16940763 B/O 20 keys (the quickbuyer from above)

-1 bud, but they refused. I think they dropped their B/O since this offer was made.

http://www.tf2outpost.com/trade/15483047

-20 keys

http://www.tf2outpost.com/trade/15415600 B/O: 24 keys

-Had an offer of 24, but that fell through for some reason.

http://www.tf2outpost.com/trade/16087811 B/O 1.6 bugs

-17 keys

Based on the sale at 26 keys, the quick buyer paying 18 keys, and the refused offers it appears this range of 20-26 is reasonable and fair to the buyers and sellers.