Yeah, it seems that Hodgdon really dropped the ball with Blackhorn. I recently got the last three 8oz cans (not all for me) from Powder Valley for 80 bucks each shipped and was glad to get it. It was $45 each for 10oz at a LGS a few years ago. If another company comes up with something similar for 60 or 70 bucks per pound then Blackhorn is finished.
It's never been 20 bucks per can. I'd check it to be sure the can is actually filled with Blackhorn.
Hodgdon currently has it in stock but it would be about $92 each for 3 cans shipped.
I really enjoy shooting my muzzleloaders but at these prices it might be cheaper to shoot .50 BMG.