Yes, and also making that house, or land, or taxes produce 4x as much energy is categorically different form reducing the cost of existing 22%-efficiency panels

Yes, and also making that house, or land, or taxes produce 4x as much energy is categorically different form reducing the cost of existing 22%-efficiency panels by 75%. That's because higher-energy-per-unit-area panels increases the efficiency of land use, which drives all the other costs you list: land acquisition, taxes, customer acquisition, etc.