More Americans are entering their 60s as renters, and many are wondering whether they’ve waited too long to buy. Imagine Mark, a 60-year-old who hopes to retire in about five years. He has built up a $2.5 million 401(k), but doesn’t have much savings in any other form of account. Mark is tired of rising rents and likes the idea of settling into a “forever home.” A $400,000 purchase seems within reach — at least on paper. But without enough cash for a down payment, Mark is debating whether to tap his reti ...