Buying a home now costs an average of $920 more per month than renting across all 50 of the largest U.S. metros, with even larger savings in the Phoenix area, according to Realtor.com data. Experts say renters who redirect that money toward saving for a down payment can build toward ownership faster than many assume. The gap is expected to narrow gradually over the next decade if current trends hold, but buying remains out of reach for many renters.