My understanding is that most of that is setup costs for retooling a fab, which requires moving around and recalibrating some very specialized equipment. The numbers I heard were dozens of engineers working a total of one to two thousand man hours to set up the process, make and verify the chips, then switch the fab back to the processes their other customers usually order. Since these semiconductor fabs have high upfront and fixed operating costs, they need to have a high utilization to be profitable - preventing anyone from having a specialized fab that makes only RAD hardened chips.

AFAIK the lower cost VORAGO designs require far less retooling so they're a lot cheaper with existing processes.