Some other things to consider are location, and going rate. If you are
a full-timer for a company you are going to make less than you would
consulting. Also, remember that the cost of living near the company
affects your salary. If you were going to live in LA, I'd say you need
to ask for oodles of cash, but if you're going to live in say... Idaho
or Montana then you can expect less. One other thing that affects
salary you can expect is size of the company. The larger the company
the more they pay (usually). Try figuring out what you are worth in
their area at
salary.com or monster or something like that.
The really big question is - what do you need to be happy? If you are
going to be happy on 20G a year because the work is engaging then why
not? If you think you'll need something more to be happy then haggle
more aggressively. Remember too that you can negotiate more vacation
if they aren't willing to pay your expected salary, or other
compensation packages (maybe they pay for your home internet).
Hope that helps!