Buyers:

http://www.tf2outpost.com/trade/9958496

-Willing to pay 11 keys

http://www.tf2outpost.com/trade/9946106

-Willing to pay 11 keys

http://www.tf2outpost.com/trade/9967671

-Willing to pay 11 keys 1 ref

Buyers looking for offers:

http://www.tf2outpost.com/trade/9283570

-Willing to sell for 11 keys

http://www.tf2outpost.com/trade/9542416

-Willing to sell for 11 keys

http://www.tf2outpost.com/trade/9267429

-Willing to sell for 11 keys

Sellers:

http://www.tf2outpost.com/trade/9922694

-Offer of 11 keys

http://www.tf2outpost.com/trade/9860126

-Offer of 11 keys

http://www.tf2outpost.com/trade/9464240

-Offer of 11 keys

-Rejected 10 keys

http://www.tf2outpost.com/trade/9913658

-Offer of 13 keys 2 ref (only has 12 keys though)

The 10-11 key suggestion seems a bit low. A lot of buyer trades willing to pay 11 keys for one.