just to add that in my experience it doesn't matter whether you buy used modules, new modules, cheap modules, expensive modules, DIY them yourself - you spend the same amount of money on modules - you just get more modules for your money (and possibly some tools - soldering iron etc and wood work equipment mainly - so you can build more cases)

"some of the best base-level info to remember can be found in Jim's sigfile" @Lugia

Utility modules are the dull polish that makes the shiny modules actually shine!!!

sound sources < sound modifiers < modulation sources < utilities