Its Blackhorn 209. The best price I have personally bought it for is 22 dollars a can.
The most stable decent price is at Powder Vally inc. on the Internet.
http://www.powdervalleyinc.com/
If you have a good TC rifle all the standard reloading 209 will work stay away from the so call special muzzle loading primers they are a rip off. If you have one of the off bread rifles you may have to have an improved.