> The only way to know the price of your labor is to interview and see what the market says.

There are other ways to infer your value. Taking longer vacations, especially off season, can illustrate to people what it's like not to have you around. If they don't miss you, it's time to move on. If they do, it's time to remind your boss.

I knew one guy who was a career employee for a Fortune 500 company, he just moved around every five years, but this guy had the ballsiest negotiation tactic I've ever seen. When it was time to discuss a raise, he'd wear a suit to work and take two hour lunches. In one case he didn't even have time to talk to his boss before his boss approached him with a raise.