If Portland is anything like Seattle, the problem is that the absurd zoning encourages developers to build larger houses to maximize their return on the investment in acquiring the land. This is based on conversations with architects and builders where I've asked about this specific problem.

This means that I could afford many newer houses if they were built out to something like 1800-2200 sqft which would still be more space than I need. But instead all new houses are built out to 3000+ sqft making them >$1m.