Read up on the lucas formula. That will teach you how to look for nutrients. Lucas uses General Hydroponics because their cheap and widely available. However he skips the Grow, and only uses the Micro and Bloom. Sounds crazy, but once you understand what plants actually need you quickly learn that brands and popular trends don't mean shit. Its all about NPK and Micro nutrients in the proper ratios at the proper times.
Powders chemicals like Maxibloom are the cheapest way to go, but you can do pretty good with organics too. Alaska Fish Emulsion (5-1-1) and Alaska MorBloom (0-10-10) is only $5 and $10 dollars per bottle and can easily last you a couple of seasons for a personal grow.