Hi Michael,
I can feel you getting in the middle of a tug of war so I"ll try not to add to that. Since one has to have a regular bathroom fan anyway you really aren't wasting money by getting one with a constant low CFM rate in addition to the high "on" cfm mode. Just think ahead while you are still in the planning stage for where and how you would install an HVR if you decide to install one later and make construction provisions for it.
Let your own experience living in the house be your guide whether to go for the expense of an HRV at a later date. That would be the smart way to attack the problem, (if there is one
).