It sounds like followinbob might be milling the individual components inside the colette, in which case there would be a substantial savings over Schoeps part. The most expensive component is $200 for the 'white plastic rings' because the active circuitry is mounted on the underside. When making 'nbox' cables, those parts are basically discarded and replaced with a different circuit, so you're essentially paying $200 for a piece of plastic. Definitely worth it to have these made... more so then the actual colette shell (which is only ~$60).
What would be really cool to do is mill colette shells that are approxamately the size of CMRs (extended approx 1 inch or so), then stuff a PFA circuit inside the colette shell rather than at the XLR end. This would be a true "poor man's" CCM.