When it comes to valuing ghost-busting businesses, the first thing we look at is revenue. Whilst they never mention how much their revenue is, we do get a glimpse into their pricing structure when they capture Slimer in the Sedgewick Hotel:

“For the entrapment, we’re gonna have to ask you for four big ones. Four thousand for that. But we are having a special this week on proton charging and storage of the beast, and that’s only going to come to one thousand dollars, fortunately.”

We never hear how much proton charging and storage is outside of the week that it’s on special, but we’re going to assume this is something Peter Venkman made up to try and soften the blow of the pricing, because who doesn’t want money off something (even if it’s made up)?

Another element the busters keep quiet is how many ghosts they capture. We see the guys catch nine ghosts in the film, including the 112.5ft Stay Puft Marshmallow Man. (We know there must be many, many more, but we’re just going on what we see.) If each of these is $5,000, that means they would have made $45,000 in the time the film was set. According to the Ghostbusters timeline the business is set up in early October 1984 and Gozer is defeated on November 9th 1984, so our best estimates are that the Ghostbusters make $45,000 over a five week period.

Assuming the $45,000 takings over a five week period are consistent, we can use this to determine the annual takings for Ghostbusters would be roughly $468,000. Not bad for a start-up in its first year! This is, of course, in 1984 money. Adjusting for inflation, we get $1,092,731 in 2016. It’s certainly enough to keep Winston in his “eleven-five a year” job.