Housing prices aren't going up because of billionaires, they're going up because of the collective action of millions of ordinary Americans, many of whom are not rich, who own houses and resist the construction of new houses near them to meet demand. Taxing the ultra-wealthy more does basically nothing to make my own housing costs less; making it legal for a housing developer to completely ignore the protests of old retired people on a fixed income and build a new condo development next to the house the old retired person bought 30 years ago would.