I think that threshhold is different for everybody. The reason I first came to this job (as an intern) was because I believed in the product and what it did for people.

Since then I've been offered a lot of money by headhunters to move to a different company (cost of living increase, then a flat 20% raise and a 20% signing bonus as well as relocation expenses). I declined it without a second thought, because I don't believe in that company's product nearly as much as I believe in mine.

All the money in the world won't help you enjoy your job if you don't believe in what they do. If you aren't happy with your job, other facets of your life will suffer because of it. I think you become a "hired gun" as soon as you forgo what you believe in for the money.