joe

there is no rule of thumb or accepted premium upcharge going from the AC condenser to the same mdl HP condenser.

However, while HVAC markets vary in pricing, I think $500 on low end to $750 on high end would be fair to both homeowner and dealer.

I will say this. On furnaces, it's clear that the market is moving toward full modulating furnaces on the high end. You should study carefully your nat gas and electric rates. I would definitely consider dropping the HP idea for the full modulating furnace. If two story, I would want two systems or at very least zoning controls.

IMO