So, my original point was to respond to the above comment: "Proof of stake requires none other than a single purchase to be gifted the right to perpetual seignorage."

My claim was that the lower ongoing expense of staking is compensated by lower rewards, so that both systems have similar profit for similar capital outlay. In setups where mining expense is almost zero, the higher rewards of mining give it much more seignorage than proof of stake.