Heya, my apologies for the ultra slow reply. My free reading time has been pretty much eliminated and I haven't been over here for months, sorry about that! My wife is pregnant with twins and between that and the business I'm usually sacked out as soon as I can be!
I've had some requests over the years for the 55 gallon drum bags, but I haven't found a manufacturer yet who can make them reasonably priced (many can't make them at all due to the size) in the Mil weight I'd be comfortable with (6.0+ for a bag this size) I've seen some at 4-4.5 mils for $15 or so, but I would have a hard time trusting 350+lbs of food in a 4 mil bag.
For us, the hardest thing would be doing quantities sufficient for a press run. For something like this, 3-4k units would be a standard run...and at $10 or more each, that's a heckuva investment for a product that might take 3 years to sell through.=) We did produce our first 50"+ bag (11"x55" at 7.5 mils for gun storage) and they're awesome, I'll run by what the pricing would be just to confirm as I know our current manufacturer has the presses to do it.
Again, sorry for being incommunicado!