You don't have to get to surface freight numbers to make SPS viable, because SPS has advantages that compensate for the higher transport cost. Those include a 9

You don't have to get to surface freight numbers to make SPS viable, because SPS has advantages that compensate for the higher transport cost. Those include a 99.5% capacity factor, a 5X higher solar flux per panel over 24 hours, and much lighter construction due to the lack of weather and gravity. As for construction cost, NASA's design would self-assemble in orbit. I linked the full study report.