When retailers don't have something on AmmoSeek.com, there are usually at least a couple of people selling stuff on gunbroker that you can't find anywhere else.
My working theory is that after the buyout, Hodgdon needed to "differentiate" BH 209 from its other powders. As a result, BH209 was made to be a "premium" product with the associated price and (possibly artificial) scarcity.