I don't think it really goes by the school. Most post-doc salaries are grant-based, hence the contract terms, limited benefits, etc. In general however, you're looking at the $30-40k ballpark.
I'm looking at postdocs now, and the salary range (in astronomy and astrophysics) is between 35k and 65k a year (higher at national labs and prize fellowships) - and there are a few in the 100k range (LANL for example).