But you assume that 100% of homeowners will buy solar at full price no matter what, with such certainty that it can even be included as a given in the budget be

But you assume that 100% of homeowners will buy solar at full price no matter what, with such certainty that it can even be included as a given in the budget before it happens. That's an unreasonable assumption IMO. Solar is not food, homeowners can choose to skip it.