Donald Trump’s starter mansion is back on the market for $45 million, after asking $54 million last year.

The massive 20,000-square-foot home at 21 Vista Drive spawls across six waterfront acres on a private peninsula in Greenwich, Conn.

The mansion’s listing broker, Tamar Lurie, of Coldwell Banker, tells Gimme Shelter that, by coincidence, she is also Donald Trump’s neighbor in Trump Tower.

She purchased several apartments directly below the penthouse triplex where he lives with third wife Melania and son Barron, age 10. “He was terrific, full of humor and style and as bright as they come. He was a very nice neighbor to have,” Lurie said.

The home boasts a three-story rotunda and a grand double staircase with an impressive chandelier, a wood-paneled library, a home theater and two pools — one indoor and one outdoor — along with a tennis court, putting green, guest house and dock.

The Donald bought it for $4 million in 1982 — around the time he was building Trump Tower. Trump, Ivana and the kids used the house on weekends and in the summers.

Ivana got the home in the divorce, along with $14 million, her own Trump Tower digs and an agreement to use Mar-a-Lago, the Florida estate, one month a year. She sold the home to its current owners for $15 million in 1998.