In the end, the cost of nutrients becomes irrelevant regardless which source I use, at least when it comes to cost in my experience. The big thing is to find something that works well for you, and hell, maybe even a method that you enjoy more. Life is all about enjoying the experience. My enjoyment in the experience comes from big yields and high quality flowers, and unfortunately my brain goes "If it ain't broke, don't fix it." If something is giving what you believe to be awesome results, keep doing you! EVERYONE has their own opinion, and they all think they are a fucking botanist. Find something that fits the budget - and if it works, it works!
Now, for the REAL info:
Even on a FULL H & G line-up, with their over-priced Amino Treatment - and 10 other bottles of additives I quit using after purchasing - my cost is only $11.36/day for 900 sq/ft of action. That lets me know after time, and systems are refined, the cost will become even less.
Just for reference sake: If you were doing a 10x10 area - the nutrients would only end up costing you $1.26/day (you would still need to buy in bulk or this cost goes up). Ok, so point being, regardless of which nutrients you use - it's all cheap in my opinion. For $1.26 a day you could have these in your arsenal: H & G's FULL line, Superthrive, Bushmaster, Gravity, Cal-Mag, Snow Storm Ultra, Crystal Burst, Azomite, Sea-Crop Trace Minerals, Age Old Organics Kelp/Fish, KelpMan All Purpose, Kelpman Kelp, Oregonism XL, Alaska Humisoil, Aquashield, Raw Molasses, Mexican Bat Guano Powder, Literally 7 different Cloning products (olivias, rootech, greenlight, schultz, dutch master, clonex, power clone). Now granted, remove some of those and your price per day drops. Some these aren't used but still figured into that cost/day.