Greetings Laura:
Unfortunately, I don't appraise timber over the phone or internet. All I can recommend is that you contact several timber buyers or local professional foresters who are experienced and trustworthy in appraising timber. Next time, market the timber before you cut the trees - not the other way around :-)
If you are interested in Illinois timber price reports, please visit the following Websites:
http://web.extension.uiuc.edu/forestry/blogs/eb94/
http://web.extension.uiuc.edu/forestry/il_timber_prices/index.html
Best of luck!