Average Closing Costs per State 2009
The survey was done by Bankrate and Illinois ranked 43rd out of the states for costs. The average costs for the loan origination was $1279 for the mortgage portion and $1207 for title charges, etc. The total would be $2486. Quite respectable compared to other states!
Link to original article State by State Costs
Illinois Closing Costs broken down for a buyer - all costs involved on the average.
This should give you at least a good rough estimate that would be needed for closing or to double check your costs on your Truth and Lending Statement from your lender.