New homes now cost $20k less than existing homes. Can this trend last?

As far back as modern records go, newly built homes have almost always cost more than previously owned homes. It only makes sense: New homes are expected to have far fewer maintenance issues, brand new appliances, and designs suited to contemporary tastes, plus they can be customized to suit the homebuyer's needs. After all, it is only in very rare circumstances that a used car would cost more than a similar make and model purchased brand new at the dealer's lot.