When Arthur Nelson, a professor at the University of Arizona, went shopping for a home in Tucson recently, he found plenty of senior citizens trying to sell their homes — but at prices far more than what they were worth. “I was amazed at the number of homes that were overpriced by about 25% where the owners were seniors,” he said. These seniors would barely counteroffer, taking so little off the asking price that it wasn’t worth negotiating, Nelson said.