How does a movie only gross $600

Come on now, that's an easy one. According to the box office and business, total amount it took in was $656 and was on one screen for a week. Assuming it was at some crummy independent movie theater where they only charge $8 for tickets, that means 82 people came over the course of the one week, and that gives you $656.

The real question is, of the $ 2.5 million budget, what the hell did they spend that on? Because the scriptwriters couldn't have been paid too much, given what a piece of crap this was.

That's just box office (1 cinema for a week). It doesn't include DVDs, Cable, Netflix etc