“American Dreamer” doesn’t so much end as peter (Ahem.) out, with a finale that feels like a series of compromises which no one wanted to winnow down.

But if you skip the movie leading up to that, you’ll be missing a lot of laughs and a tale that takes that “Peter Dinklage as sex symbol” thing about as far as it can go.

He plays a grumpy, broke non-tenured college economics professor who is obsessed with the only real way to accumulate wealth and security in capitalist America — real estate — especially real estate he can ill afford.

First time feature director Paul Dektor and screenwriter Theodore Melfi of “St. Vincent” and “Hidden Figures” tell us a “true story” “sort of” about an economist who knows a great deal when he sees one in the classifieds, but who doesn’t wholly consider the fine print.

It’s a comedy about capitalism as it relates to the Big Questions in Life — “What do we need to be happy? What do we want?” and “How far” is “one willing to go to get it?” It’s about the fantasies we lose ourselves in.

And it’s about the animal magnetism of Dinklage, linked to another amusing turn in a long career of them by Oscar winner Shirley MacLaine, with very funny supporting work by an ensemble that includes Matt Dillon, Danny Pudi and Danny Glover.

Dinklage is Dr. Phil Loder, unhappily teaching “Cultural Economics” to “spoiled d–k weasels” at Massachusetts’ Brockton U., a drinker and frustrated novelist surrounded by “twat waffles” in the faculty and pestering his department chair (Pudi) for a parking spot for his aged Saab, the car of choice of academics all over America in the ’80s and ’90s, and in movies about academics forevermore.

Phil, we learn, has this long-running relationship with a man he calls “Ass—e,” who refers to him by the same contemptuous nickname.

Dell (Matt Dillon, in grand form) is his reluctant real estate agent. Phil shows up for every high end open house on Dell’s client list, with every mansion millions of dollars beyond Phil’s modest price range.

To Phil, Dell is a lowly “dirt pimp,” someone built to be abused. “Everything about me screams SUCCESS,” Dell counters to Mr. “No equity, no money, no tenure,” who seems born to waste his time.

Phil fantasizes about living in these palaces, and imagines a beautiful wife (Rebecca Olson) and her sister there with him. It’s his “American Dream.”

And then he spies the classified ad for a $5 million dollar mansion available for $240,000 if you take it “with live-in.” The “live-in” turns out to be the rich old lady (MacLaine) who owns it.

The real-estate savvy filmgoer may wonder about this screenwriterly fantasy “deal.” Elderly Astrid doesn’t expect care-giving. She doesn’t seem cash poor. Why would she “sell” this house for so little just to have a stranger move in with her? It never makes sense.

Phil sells everything he owns — grumpily — cashes in his 401K and unloads the car. He may have to eat sandwiches the rest of his life, and ride a scooter to work. But now he’s got his piece of that “dream” he’s only been able to dream about.

The script, from this point on, veers back to and fro with accounts of Phil’s sex appeal to one “consenting adult” student (Michelle Mylett), to a probate lawyer who turns out to be one of Astrid’s “kids” (Kimberly Quinn) and examples of the sorts of clashes we might expect anyone to have when living in a house with Shirley MacLaine or a character she plays.

Phil has lots of accidents on the property. Astrid’s “kids” mean he has “a contested WILL in my future,” and not a clean path to ownership.

A wisened, too old for this you-know-what private detective (Glover) gets involved and the accidents pile up and where WILL they take this narrative before all is said and done?

The screenplay has much that’s fun about it, with zippy one-liners, droll aphorisms and sharply-drawn characters who clash and crack-wise with one another. Dinklage wears this role as easily as any he’s taken, and he clicks with Dillon, Glover, Quinn, Pudi and especially MacLaine.

But there’s real indecision on screen here, as if no one could quite decide where to take things, what would feel “true” vs. what might be “satisfying.” And the organizing device of writer Phil word-processing his “novel,” chapter by chapter, is even more lame here than in the other 754 movies its turned up in.

And yet there’s just too much fun here to miss, even with “Dreamer’s” flaws. Dinklage savors every man-of-letters zinger, and gives a toast for the ages as a kicker. Remember this one, because Phil did, and Dinklage performs it like a lad who appreciates a great Irish toast his own self.

“Here’s to a long life, and a merry one. A quick death, and an easy one. A pretty girl, and an honest one, a cold pint, and ANOTHER one.”

Rating: unrated, sexual situations, profanity

Cast: Peter Dinklage, Shirley MacLaine, Matt Dillon, Danny Pudi, Kimberly Quinn, Rebecca Olson, Michelle Mylett and Danny Glover.

Credits: Directed by Paul Dektor, scripted by Theodore Melfi. A Vertical release.

Running time: 1:38