No, a VCO is still going to cost at least $200+
but paying $500 for a basic 3U rack/case!! I’ve built a 6U 84P setup for just over $100 (not including psu) Just buy the rails, find some “junk wood” (I used an old chest of draws) and go to http://www.doepfer.de/ for instructions.
Then the other basics – cables, multiples,& attenuators ….the more the better, but even a Doepfer mult is going for $50AU. You can (I have) built one for $13AU…and that was paying top dollar for a “blank panel”.
Thank the gods for China/eBay.