Free: Contests & Raffles.
Did you try one of the GOEX distributors, the GOEX site says you can buy direct from a distributor.Here's the link: http://www.goexpowder.com/distributors.html
I bought the last I got in 1975. I belonged to the Yakima club at that time. We ordered quite a bit. I believe I bought 35-50 pounds of ff, fff, and 1 can of ffff. I am still using on it. I believed it cost us either $1.50 or $2.00 a pound. The powder was delivered to a armoury in the WallaWalla area. One of the club members was a Pepsi truck driver. When he was in Walla Walla he picked it up in the Pepsi truck. As I remember he hauled 1,500 pounds in mostly 1 pound cans. There may have been a few 50 pound containers. I think that would cause a ruckus now days.
I seen some at Lynnwood Gun a while back.
I emailed a friend who works at the White Elephant. He said they still sell black powder. Many restrictions, like only 5 pounds at a time in store. Permits etc keep price up, about $21.00 pound.