I always tell junior developers to think of an interview as a first date.  You are trying to figure out if a second date/interview is a good idea, and it really takes both sides to determine if moving forward is the right idea.  I recently went through a set of interviews, all the way to an offer and turned them down.  Not because of money, but more of something I couldn't put my finger on, a sense that something wasn't right, whether it was fit or the job, or something entirely else.  I still can't say exactly why I ultimately said no.