just built a 126 HP rack for ‘development’ purposes…
(current projects are for terminal tedium, bela pepper… and later bela trill
)
eurorack need not be expensive…
rack kit was about €100 and some scraps of wood, trivial to build, and a couple of hours of messing about 
whats nice about the DIY approach, is after the main dev works is done, I plan to adapt/rip this apart, and give it a new form (a specialised controller focused rack based of bela trill) , reusing all the parts from the kit… it could also be extended very cheaply if needed.
of course, now means i need to go re-arrange my main rack… as it nows got a bit more space!