Forget 5 times, you should be getting paid 300 times that other guy. From the Wall Street Journal, via Kedrosky:

One top-notch engineer is worth “300 times or more than the average,” explains Alan Eustace, a Google vice president of engineering. He says he would rather lose an entire incoming class of engineering graduates than one exceptional technologist. Many Google services, such as Gmail and Google News, were started by a single person, he says.