AP Photo

Less than 24 hours after the richest team in baseball won the World Series, its biggest foe began reloading for next year by making a trade. The Boston Red Sox are among baseball’s most affluent as well, so giving up a couple of prospects to the Florida Marlins for high-ceiling outfielder Jeremy Hermida amounted to a no-brainer.

Never mind that Hermida will cost around $4 million this season and, depending on Boston’s other maneuvers, might play a fourth-outfielder role. The Red Sox, just like the recently crowned New York Yankees and another handful of teams with payroll flexibility, can afford such luxuries. In a market that could see an overload of young, arbitration-eligible players deemed...