Tis the season for.. job offers! I was asked recently for help on negotiating an academic job offer. Here is an article that offers succint, sage advice:
"Go Ahead, Haggle" by Rebecca A. Bryant and Amber Marks, of the Graduate College Career Services Office at the University of Illinois-Urbana.
The bottom line: negotiate! In my words: Ask for what you want. The worst reply you could get is no.