My friend used to work for a movie theatre, and the markup on the food/drinks was incredible. The popcorn is so cheap that they would give us a huge bag of popcorn (a garbage bag size full)... But they wouldn't let us use the containers because the containers were worth more than the popcorn itself. Same with drinks. So however much popcorn costs now at a movie theatre (I haven't bought food when I goto see a movie for ages) ... The food itself is probably worth pennies, and the tub itself that holds the popcorn is probably worth maybe a dime. Pretty big markup assuming a big tub of popcorn costs you like $5.00
The high markups for products aren't only to pay for a company's employees' salaries, its also so companies can have a huge profit that translates into big dividends for shareholders or increasing stock prices. Since in most corporations, CEO's and the like are elected, there is the possibility that if the shareholders aren't happy (and the thing that makes them most happy is growing profits) ... they will vote for a new person to replace you, and you'll be out of a job.
Now I'm not talking about shareholders that own 100 or even 1000 shares ... I'm talking about the people or companies (like a company who operates a large Mutual Fund) who own enough of the corporation that they can describe it in percentages (ie. I own 5% of XYZ company). These people have huge voting power when company elections come up.
I dunno if all corporations work this way, but the companies that I own stock in do voting like this... In any case, that is partially why there needs to be high markups. So CEO's and other important people can have a profitable company and make your shareholders happy so they'll keep their jobs. If we were simply talking about a company that tries to break even after paying its employees enough to live on, then prices would probably be much lower! I believe Florida's Natural which is a Co-Op tries to operate like this.