Are you concerned that if you make prison too expensive society might resort to capital punishment to reduce prison costs? Or we end up releasing prisoners who are legitimate dangers to society.

And to be clear, I'm opposed to capital punishment and dangerous conditions in prisons. I'm just pointing out that I don't think your argument is very good. If you think we as a society are willing to flippantly put people in prison because it's cheap I don't see how you can trust us to no resort to other flippant measures if the cost was high.