[stomachmonkey]

Now I will say that a friend of mine just had this experience. Got a final offer letter and realized that the benefits package was an issue.

He needed them immediately and the employeer had a 30 day waiting period.

He spoke to them about it and they made an exception for him.

I guess it depends on what you need to negotiate, if it's monetary based I'd do it up front. Something else like a start date is not a big deal.

Scott