I would start with intelijell 62 hp palette case. Add the Umidi CV interface tile, and a mono output 1u tile. So 450-500 would get you started. I 'm only suggesting palette case as a starting case because it and Umidi has good resale value.
This example case can do a lot in a small form factor.

[]https://cdn.modulargrid.net/img/racks/modulargrid_2826882.jpg?1744752308
Someone needs to instruct me on how post a proper rack. I must be thick or something.