Complex sentence: More significantly, balls were kept in play until they were mangled, soft and sometimes lopsided: a baseball cost three dollars, equal to $today (in inflation-adjusted U.S. dollars), and owners were reluctant to purchase new balls.
Split into simpler sentences: More significantly, balls were kept in play until they were mangled, soft and sometimes lopsided. During this era, a baseball cost three dollars, equal to $today (in inflation-adjusted U.S. dollars), and owners were reluctant to purchase new balls.