When I was growing outdoor in the late 90's I would use my dad's compost from a 6'x6'x5' Box he made in 77. That made my plants flourish and it was free. I had that and some guano, potting soil, little peirlite and a little fish emulsion in the water. That other stuff really isn't that expensive at all. Best of all it was simple. Really damn good results too...
Inside would be a whole other story. On that note, they are some very cheap and effective nute regimens out they. They are not all that expensive.
Good Luck!
If I was growing outside today my recipe would of course be different. Yet, I would still use that compost! literally 20 year old compost all from moms byproduct from the kitchen and dad gardening a 1/2 acre: Veggie skins, stalks, egg shells, grass cuttings and leaves. Stuff that fell out the bottom of that box was gold!