Irrelevant; increase of efficiency by 1% point would have a bigger impact on bottom line than halving the price, almost all expenses in building solar installations are "balance of system" costs, not panels.
Solar is already cheap, in locations closer to the equator it's typically the cheapest source of energy. What needs to happen is cheap storage, even if you have free solar energy during the day it's still too expensive to provide battery power during the evenings.