Here are some more points:
- building restrictions are overturned or overruled, but only after expensive lawsuits. These are impossible for small builders to do but routine for large builders. They are also better financed and more experienced than the municipalities they are suing, so they eventually win after several years and millions of dollars.
- With or without a lawsuit, it's easier to build get bigger houses on bigger lots approved. That's fine for the builder - all they need is an ROI - but it eliminates the low-end option.
- People move often so resale value is a very high priority, especially for first time buyers. I live in the suburbs and would love to have a condo, but I would never want to try to sell a condo in the suburbs so I bought a house instead. Condos and townhouses are cheaper and would serve many people's needs better, but these are marginal properties that will suffer most in a down market.
- External factors (proximity to transit, good public schools, proximity to workplaces, etc) reduce total cost of living and increase home prices by roughly the same amount. In Chicago suburbs, Naperville has excellent schools, Aurora not so much. Identical houses across the school district boundary are over $100K different. Being close enough to walk to transit saves (at least) $40/mo on parking but more like $100 when you include gas,etc, which corresponds to about $10-15K in house prices. But it saves time, which can be valued very highly, so a house 1/3 mile from a commuter rail station would cost $75-150K more than a house a mile from the station. (probably a bigger deal in Chicago/NYC/Boston more than anywhere else). Ditto if you don't need private schools.
- As supply goes down (or grows slowly), houses are competing for a smaller slice of the upper end of buyers. If only the top 50% of potential buyers can afford a house, the needs of the bottom 50% are ignored. If only the top 10% can afford it, the bottom 90% are ignored. So if most potential buyers are DINKs (dual income, no kids), then new construction will be 1-2BR condos/townhomes, with very few 3BR. The 3BR units will be much more expensive both because they are larger but also rarer. If most buyers are families, the sizes might start at 3BR and go up and there probably won't be any 1-2BR at any price.