The Illinois toll road system is pricey.
I live in the Chicago southwest burbs. You should know that the Tollway changed it's pricing structure for trucks, trailers (and RVs) in January 2020. Recently we took a short trip to southern Illinois, which involved 4 tolls (r/t) on I-355 (to intersect with I-80). Cost towing our Subie was $23+change. They rate a tow vehicle as Small, Medium, Large. Our Class C and car combo is rated as Medium.
Could save half by disconnecting the car and have the wife drive it through.
If you stay on I-80, you should have only 1 toll though.
Here's the current rate chart