Even though the Giants got clobbered in last year’s Super Bowl, Tiki Barber came through the postseason a full-fledged New York media hero. And like few pro athletes, he’s embraced the city in return. He and his wife, Ginny, have just made their New York relationship official, dropping $1.3 million for a three-bedroom apartment in the Oxford, on East 72nd Street. Brokers say the 1,800-square-foot spread was a bargain, as three-bedrooms in the building have gone for $2.1 million. How did the Barbers score such a winner? The apartment’s on a low floor and has better views of the neighbors’ walls than of the river. (Maybe that’s why it sat on the market for six months.) On the plus side, the building has a health club with a pool, so the running back can get a full workout without making the jog out to East Rutherford.