I didn't see a location listed. I believe so much depends on this. Weather extremes, types of storms, average temps. If I'm not mistaken modular provides better insulation, but if you are in a hurricane prone area, I wouldn't go modular.

So I believe location must play a big role making this decision. A lot of people in Florida choose frame houses for their insulation benefits, but come hurricane season wish they had CBS construction.

Also, as someone wrote, I believe you will see the same percentage increase in all types of construction and not just modular.