That is maybe for the lowest cost, lowest quality houses in the US.

See "Average Construction Costs of Single-Family and Multi-Family Residential Buildings Per Square Foot in the U.S." on [1] for costs within major cities, you will see that costs are much higher than that, even if not 1k psf.

[1] https://www.togal.ai/blog/the-average-cost-to-build-a-house-...