Maybe one day this will be a problem but for now I already have a 6U104HP DIY flightcase (260€) and lots of room (because the neutron goes). Main reason I prefer to rack these semimodular synths is for transport and to keep the system as compact and tidy as possible. If one day I end up needing more room I can always put them back in their case.
The expensive part of eurorack is not the case, is the modules. A 6U104hp full of eurorack modules goes for around 4000-5000€, the 270€ spent on the case is just a 5%