I think the suggestion to slow down is a good one. Irrespective of money, every module you buy has a cognitive and spatial cost. Moreover, unless you intend to copy someone else’s setup, you don’t know what you lack. You’ve already said it’s for live and studio which implies a lack of focused intent for the system. I would do two things before pulling the trigger on the modules.
- Think carefully about what (in specific musical terms) you want to achieve.
- Use the three Moog system extensively (and ideally exclusively) for a few months.
If modular is the way to get to your musical goals, I suggest first deciding on live or studio for the rack. In particular a live rig may be able to work in the studio but has to stand alone (so I think this is your intended direction). The first suggestion above is intended to help avoid filling a rack with cool modules that end up not supporting your goals or forming a coherent system: think about your end goal with every purchase (unless you’re end goal is to have lots of cool modules). The latter is about guiding your design with experience and need.
With your three Moogs you can make music standalone: there is no inherent deficiency so you don’t need to augment it. Once you start making music and performing that setup you’ll get a clearer understanding of how you like to work and what you feel yourself missing. As a rule I’d say try to wait at least a couple of months between modules purchases. Specifically, use your system for a couple of months before asking: what is holding me back from making the music I want. This may be nothing (best case), a specific function (which you can find a module to fulfill or figure out to get from what you have) or something more fundamental (you want to work in a different manner). Either way, that waiting period will help you guide your purchases and refine your design.
Another risk in buying modules as a set (without clear musical intent for each) is that it tends to be hard to let them go. Every module you get rid of can feel like an opportunity lost. The result can be a hoarding mentality: starting another case for cast offs, then four cases down the line, finally realising what you wanted in the first place. Taking your time can help you figure out what and how you’ll perform and incrementally walk toward that ideal musical setup (modular or otherwise). Designing that setup is an iteration and the music you make a collaboration between you and the machine you design: design it with care, to be uniquely yours.