Alex Rodriguez just bought a $7.4 million acre of land on tony North Bay Road in Miami, with striking views of the city and Biscayne Bay, reports The Post’s Jennifer Gould Keil. The Yankee slugger, who lives on Central Park West during the baseball season, “always wanted to be on the beach, but [ex-wife] Cynthia never wanted to,” said a source. The price is $1.5 million less than what the previous owner paid for the land in 2006. A-Rod’s neighbors will include Calvin Klein, Matt Damon and Ricky Martin.