Good job offer advice from the Marketing Headhunter. I'd say something about a bird in the hand, but I think we already determined that I don't like to touch raw poultry.
Anyway, I've had candidates decline our offer and then want to revisit. The hiring manager is left thinking " what changed?". It's like telling someone you'll go to the prom with them because you didn't get asked by someone better. How do you make the original asker feel good about the situation? And is it possible that your perception of your marketability isn't consistent with reality. I hate to talk about it on those terms, but there it is...we all have to be real with ourselves though, don't you think? It helps if you think about your skills as a package you are offering to a hiring company versus offering you, yourself. If they say no, it just means they are looking for a different package.
It's a tough situation for the job seeker which is why I like the Headhunter's advice to document what you are looking for up front. This makes you think it through. It becomes real when you put it on paper for yourself and it makes compensation not the main issue in making a decision. It allows you to put the compensation issue aside (does it meet my compensation needs; yes or no) and make decisions based on what you love to do, where you want to be, who you want to work with (or more grammatically correct: "with whom you want to work").