jacks 3-2-1. Can buy generic versions of the 2nd/3rd parts, but use JR Peters "Jack's Part A 5-12-26" .
I'd also suggest getting the no-nitrogen Part A 0-12-26. It allows dropping nitrogen in flower while maintaining calcium levels better. Caclium nitrate and epsom salt (magnesium sulfate) are the 2 other parts of this setup. These can be generic products and will be molecularly the same. I buy the 8lbs non scented equate brand epsom salt at walmart, for example. Relative to proportion of dosage, 8lbs pairs will with the 25lb bag of Part A. There's a brand called yaraliva that sells 50lb bags of calcium nitrate for 30-40 dollars.
Probably averages out to 30-40 dollars per year for year round growing in a 4x4 or 5x5 sized tent. Can't beat it. I have a PPM breakdown for formulas in germination week, week 7 and at some point deeper into flower - animal mints, kush mints or mountop mint diaries. their instructions are a good starting point too. I think it's a bit high in N, but whatever works.
If you buy in bulk, it's less than 4 cents per gallon mixed. Buy some 25lbs bags ever 3-4 years or more. Dry nutes store indefinitely assuming common sense storage. It might cost more up front, but it is cheaper in the long run.
Fertilizer is cheap. Paying a premium for it is totally unnecessary.