Well, buying single ingredients would be a lot cheaper and it isn't that hard to find a good recipe.
Hmm, maybe you could take 2 cuttings from a plant, plant one in fox farm, the other in an organic mix you made, and compare results.
I'm using blood meal, bone meal, kelp meal, and jersey greensand for my plants.
It's a pretty basic recipe, you can find all the supplies at a good nursery.