Several years ago, just before the housing market tanked, I owned three duplexes (making three mortgage payments each month) while only making $10.50/hour. (between jobs at the time.)  So working class people can indeed buy property.

Since then I sold two duplexes, and currently only own one duplex.  The rent from one side pays the entire mortgage, property taxes, and insurance.  I live for free! If the city passes a tax levy, bond, or increases a fee, which increases my property taxes, I increase the rent on the side that I rent.  The renter ultimately ALWAYS pays for property tax increases, and all repairs.

Your supply-and-demand strategy won't work.  If an investor can't make a profit, they won't build.  If the rental market is saturated,  and goes south, housing projects will be foreclosed.