Li’l value in this judge’s opinion

NOBODY should be surprised that state Supreme Court Judge Arthur Engoron ridiculously undervalued Donald Trump’s Mar-a-Lago at a measly $18 million — drawing incredulous howls from property professionals who assessed it at $300 million.

Engoron — who was elected without opposition thanks to the Democratic stranglehold on judicial choices — makes no secret that he hates all developers. So in every case that involves real estate, Engoron is plain nuts.

His rulings in major New York City zoning cases were twice overturned by the state Appellate Division, because his decisions showed he had no idea what he was talking about.

When developers wanted to put up a few tall towers north of the Manhattan Bridge, some locals sued to block the project because they said it violated zoning. Engoron (inset) found that it didn’t — but he just didn’t like it anyway.

He said, “You can’t just do this because the zoning allows it. I just can’t believe this is the case.”

Alas for Engoron, it was the case — so the higher court reversed him.

Last year, Engoron held up a plan to build new housing on a parking lot near the South Street Seaport because he claimed the developer had an “impermissible” relationship with the Landmarks Preservation Commission. In fact, the judge just didn’t like the plan. That decision, too, was tossed in a unanimous decision by the appeals court.

That Trump historically has wildly overvalued his holdings is hardly a secret — his boasts were long a laughingstock among real-estate pros.

But whether that gives Engoron the authority to strip him of his entire company will surely end up in a higher court. If history’s any guide, Trump will soon be taking a victory lap.