When you get a job offer with a salary, are they expecting you to negotiate a higher offer?

It depends, if you're in a major corporate structure, especially retail, jobs usually have a set wage. Other than that it never hurts to ask. Check salary.com to get an idea of what the position pay should be. If you're not planning on taking any of the medical than you can use that. Your employer is usually putting in some money when you sign up for medical and if you won't take medical than feel free to say so and that maybe some of that money they won't be spending on your medical can go straight to you. Don't forget though that money isn't the only compensation, if they don't want to give you more money maybe they can give you an extra week of vacation or something like that.

Yes, it is expected. Do research on your position to see what the ranges are.