Several months ago I changed jobs and was actually recruited by the company that I now work for. I did, however, negotiate several items .
Keep in mind that most things are negotiable -- I actually believe that everything is negotiable (also depends on the position) and it never ever hurts to negotiate. Remember, the worst you can be told is "No" but at least you asked or negotiated something that you can live with. Also, it's much better to have all the information/numbers in front of you prior to making a final decision.
For the new position that I'm now in, I did a spreadsheet (it was very easy to put together) and compared all the benefits (medical, dental, pension, etc.) and salary although I did get a subtantial increase in salary by just changing companies. For healthcare, I compared my out of pocket cost with what the company was putting in. I'm divorced and responsible for my son's health care costs as well. For me, its very important to have good coverage and, without it, you could end up with a huge medical bill. I also compared pension plans which is a very important item. I tried to distance myself from making any decision, even though the new position looked attractive, to keep me focused on the whole picture.
In terms of vacation, for me, my salary pays the bills and that is what future raises are based on so I'd rather start with a good salary and go up from there. Certainly find out what you will start out with (for vacation) and ask if that will increase at any time, given length of employment, etc. What is the plan for future raises, compensation, etc.?
Bonuses are gravy so don't count on it until its "in the bank". If this is a new company, it could be a while before you see some healthy bonus checks.
In terms of negotiating salary, I've always provided potential employers with a "healthy" range and I shoot high, given what I know of the market in that profession. You need to ask for a salary that is in line with the market so you may want to check that out beforehand. Pricing yourself out of the position is never a good option -- its better to be open to future raises.
Opportunities for growth with the company -- if you are interested in staying there a while ask about other potential opportunities that may come up, so they know you are interested in taking on a new role/responsibilities.
Personally, I feel that it is important to look at all the pieces of a new position and salary is only one item, although it is important.
Good Luck with your deicision,
- Vivian, MN