What is the challenge with Illinois? Its property taxes are among the highest in the country. The average rate was around 2.07% of a property's total value, making it second in the nation behind New Jersey. Combined with a sales tax average 8.89%, also the seventh-highest in the country, so rest assured that Illinois knows how to extract revenue from its residents.Illinois residents are paying approximately 9.9% of their income in combined state and local taxes, which gets the Prairie State just inside the ...