yeah, 12 or 16 cubes is something like $5-6. i just saw beefheart at the grocery store, $1.50 or $1.99 a pound. it would be much cheaper to make it yourself, and you could add in veggies or fish vitamins for extra nutrition. you'd just have to trim it, but you may be able to go to a butcher shop and have it trimmed for you. would probably cost a little more though.
It might be a good idea to get a very small amount of beefheart to see if your fish will eat it. I have discus that gooble it up, others that won't touch it.