Curious - I'm surprised to hear you folks characterize the hydroponic stuff as premium and overpriced. I use this and find it quite economical. Together, both 1 gallon bottles cost $45. As you can see, the recommended dilution is 3/4 teaspoon per gallon (I use 1/2 teaspoon per gallon). There are 768 teaspoons in each gallon bottle, yielding 1024 gallons at the recommended dilution rate. Cost is just under 4.5 cents per gallon.
By way of comparison, consider fish emulsion. I pay about $13 for a 1 gallon bottle of Alaska. Recommended dilution is 4 tablespoons per gallon. There are 256 tablespoons in a gallon, yielding 64 gallons. That's 20 cents per gallon - roughly 4 times the cost of the hydroponic stuff. Not sure about miracle gro all purpose plant food (I don't have any on the shelf to check the numbers) but I'd guess it stacks up pretty well. It's certainly way cheaper than the single use things you screw on to their proprietary hose-end sprayer.
Scott