Star 80 is about many things, but above all it is about the dark side of the American Dream. It is a counterpart to Arthur Miller's Death of a Salesman, because it depicts the disillusionment and self-destruction of a self-made man.
Snider believes in the American Dream, that if you outwork and out-hustle everyone else, and have a marketable product to hawk, you will be successful. It so happens that Snider's product is sex. Snider rises up through sheer determination (visually depicted in the opening work out scene, in which he pumps iron and does push-ups until he's on the verge of having a stroke). It also helps that Snider has no moral principles that hold him back.
Paul achieves the pinnacle of his desires when he gets to visit the Playboy Mansion. He not only gets the opportunity to socialize with Playboy Bunnies, but he gets to meet his spiritual father -- Hugh Hefner. Hefner is another self-made man who has turned sex into a big business, but unlike Snider, he is socially respectable.
But Paul blows it when he gets too familiar with Hefner. Hefner takes an instant dislike to Paul. As Dorothy rises up the food chain in Hollywood, getting roles in TV and in film, Paul finds himself banished from the charmed circle of Hefner's Mansion and he thereby self-destructs. All of his projects -- opening a male dance club, trying to get a waitress bimbo into the Mansion to meet Hef -- are failures. His wife drifts away from him, having an affair with her director.
Paul is out of his element in L.A., and soon crashes and burns. Fosse provides imagery and conceits of "falllng" and "crashing" -- such as the scene when the loan sharks dangle Paul out of 14-story hotel window, and Fosse's camera swish-pans sideways and downwards to give us an uneasy sense of vertigo and impending doom. This motif continues in the carnival scene, as Fosse inserts quick shots of amusement park rides whipping downward and sideways. There is even a doll perched precariously on a book shelf in Aram's office -- probably a symbol of Dorothy. There is also a telling line of dialog, when Dorothy's mother asks Paul what he will do if she doesn't sign the consent form, and Paul says, "I'll jump out a window." In the final rape/murder/suicide scene, there is an emphasis on falling -- and the final shot looks down from high above, at two dead, bloody bodies that seem to have dropped into Hell.
Fosse's use of pop music is superb, and revelatory. "Big Shot" by Billy Joel is about egomania fueled by coke, and not only does Paul want to be a big shot in Hollywood, he takes the ultimate "big shot" when he blows his brains out with a Mossberg shotgun. The Band's "Up On Cripple Creek" tells about a man who lives off his girlfriend. There is a lyric about betting on a nag, which is visually underlined in another scene when Paul changes horses on a merry-go-round (further expressed when Paul "changes horses" by trying to turn a bimbo waitress into another Dorothy). Billy Joel's "Just The Way You Are" provides ironic commentary. Paul is not only dissatisfied with himself, but he constantly strives to change Dorothy from a naive teen into a mature, sophisticated woman -- and he succeeds too well, as Dorothy grows up and realizes she must get away from him. Rod Stewart's "Do Ya Think I'm Sexy" is appropriate, as it provides auditory reinforcement of Paul's eager desire to please and make a good impression.
There is a lot of thought put into the film. Geb is not merely a doctor, he is a plastic surgeon, and has moved to West L.A. to flourish in his trade. His profession is all too apt in a world in which surface appearance is everything. He also gives the key speech in the film, in which he reminds Paul that in L.A., "There's always going to be someone with more money than you, someone with a longer penis than you." That last observation really gets to Paul. He feels grossly inadequate and must overcompensate in every situation. Geb also makes the questionable claim that the Rolls in his garage is just an investment, rather than an emblem of conspicuous consumption.
The film has a Shakespearean quality. Hefner is the King, Dorothy is the Princess, Aram is the Prince, and Paul is the Bastard. People like Geb are the loyal attendants in the King's court. Some, like Aram, are bestowed with the favor of the King, while others are dispatched into exile. Paul can't take the rejection, and kills Dorothy and himself. If the sexual revolution was really a Pandora's Box, then Paul is one of the demons let loose to hover ominously over the orgy.