Kinda difficult to do a Buchla-esque poly modular for $3k. Plus, what you have there isn't going to work because there's a lot of parts missing...no VCAs, the CV input section of the VC Mixer is missing, no output stage, etc. And since West Coast systems tend to use complex oscillators (pricey), just four single VCOs isn't going to get you there.
As for generative, that can get even spendier, since then you're in the realm of multiple modulation sources, random sources, sequencers, quantizers, logic, and so forth. In theory, you could fit it into 2x84 hp like the above, but you'd have to use a lot of very small-space modules, and it would wind up turning into a patchcord thicket. Put that together with the polyphony, and you've arrived at a system that's much larger than the cab above, and which costs quite a bit more than $3k CDN. You might want to scale this idea down somewhat...