But this house was sold to average humans, in contrast to Savile Row suits.

I think we need to embrace the healing power of "and" here: the modern amenities and size are great, but we've lost something very significant in the materials and aesthetic quality (regardless of taste, I have seen well done houses in nearly every style save brutalism) far out of proportion to what we pay for housing.

I don't think so. From some not-too-reliable numbers I found in Google (if you have better ones, feel free), the median house price in 1925 was $6,000. This Sears house cost almost 60% of that just for materials. No land, labor, mechanical...

If we apply your 4x adjustment, the Sears house cost about $14,000 as built. That's more than twice the median house price of the day.

This was a house for wealthy people.

And not even all of them: "Price does not include cement, brick, or plaster"