The cost of the Zombie in the RH already assumes you are not growing the body (if you are then it is a normal biological robot).
The KCr10 listed is the cost of the basic brain alone (the advanced ones are MCrs). Even the basic brain interfaced to a biological body is far more expensive than the non bio equivalent. It is too expensive in my opinion and I'd have liked to see a simple scaling from the normal robot brains rather than a new table). However there is probably a lower limit of cost as the brain body interface is likely as complex as a neural link (which is KCr30) plus an extra cost as the robot brain replaces the brain rather than merely substitute some of its functions.
We can presume perhaps that governments will be able to make bulk savings and the costs might not be as high for them.
Where your dubious government will make savings will be in reusing the same brain in multiple bodies once they wear out. That KCr10 is much less if it can serve for centuries being grafted onto different bodies as they wear out. Delightfully sinister

Or possibly this could be likened to reincarnation and a positive spin put on it.
If you were simply looking for cheap workers pressed from death row, it would be cheaper and easier to lobotomise them rather than build a robotic brain and implant it. Or just fit a cortex bomb to ensure compliance.