[erickj]

These houses still had to be built, hooked up to plumbing, wired for electricity, have a lot cleared and excavated, concrete poored... Also you still need to decorate and provide appliances.

Add all that in and you'll see theres a few 100k worth of additional work not in the kit

So that $52k price is really just for building materials and plans, but doesn't include land, permits, building costs.

[worstspotgain]

The 1920 all-included price would not have been tripled. Consider that the median US house price in 1940 was $2938, or $66K in current dollars.