Buy bulk, dry nutes. It may last 5+ years if you don't grow much per year, but the shelf life is decades, so it's no problem. A bigger cash outlay today, but cheaper over time. 25lb bag of jacks, 25lb generic cal nitrate and 8-10lbs of generic epsom salt (end up with ~7-8lbs cal nitrate leftover when 'part A' is exhausted) will be just under 4 cents per gallon mixed. Think it's ~3500 gallons, and again, you have 1/3rd of the cal nitrate leftover. So, you may spend 100-120 USD day one, but it'll be years before you need to buy any more.
it's actually cheaper to buy the 50lb yara liva cal nitrate than the 'jacks' branded cal nitrate 25lb.. even if 1/2 of it rots, still cheaper. 30-35 usd for 50lb vs 50-65+ usd for 25lb. Talking in total closer to ~3 cents per gallon mixed.
Like buying a light with higher efficacy, it usually is a better financial decision in the long-run even if a bit more expensive day 1.
if you can formulate a no-till soil that can keep a plant fed properly with minimal or no additional fertilizer, that's awesome, too. I don't know what is cheaper, but you'd probably still have to buy in bulk and the less water-weight involved, the cheaper it'll be. Anything 'organic' probably won't have a long shelf life.