I agree with what everyone has said so far.
Money is really out of your hands in both private and academic jobs. Academics usually have payscales that are based on years of experience, rank, and give increases yearly for cost of living. You really have no room in negotiating your salary or contract for the most part. I do think RADONC is right on the money....you can negotiate protected time (for research), and that is probably most important anyway.
As for the private market, again, as a new grad, you'll have little room to negotiate numbers. You may be able to get an extra 10K, but the reality is that most groups know what they are going to offer and stand by it. Certainly, and outstanding candidate might be able to garner a little more, but in the real world, you're just another physician. In private practice, you can negotiate other benefits, however, and may even be able to negotiate the terms of partnership - ie less years. In the end, however, your starting salary really means nothing because within a few years your be making double or triple that amount anyway.
my 2 cents.