Exactly what Jim said. Consider this: in January, I started investigating a modular setup. In February, I bought a case (7U Intellijel - the 1U is practical e.g. for a Quadratt, which is 4x where Triplatt is 3x) and a first series of modules. I think it filled about 60-70U. No way, I thought, that I'll fill that up any time soon!

This is where I am at now:
ModularGrid Rack

I'm in doubt if I want a second Intellijel 7U and connect them together, because I'm not finding the build quality too great. The other option is to buy a completely different luggable 10U or 13-14U, preferably somewhere 120-160HP.

Modular playlist on SoundCloud