Go through your results for flights to Champaign in USA with Netflights. Although American Airlines usually has the best prices, it's best to double check what's available for your travel dates.
Flexible on dates? Conducting your search by month allows you to compare prices to Champaign throughout the year. Accommodation prices will also be higher at this time of year.
Look out for flights with American Airlines, as they often have good deals. Or broaden your search by looking at other airports in USA.
For even more options, check what other airports you could fly to Champaign from. You might be able to make a saving by going from a different airport or city.