Plan to travel by bus from Chicago to Cedar Rapids. When I try to book online, both Burlington Trailways and Greyhound, want to charge processing fees. If I book at the counter, are there any processing fees?
In my experience similar fees still apply at the station.
Moreover, Greyhound has started charging extra for tickets sold at the station vs. online - since this route is run by Burlington Trailways this might not be the case.
If you can find a way (like a cab or uber) up to Cedar Rapids from Iowa City (for Burlington Trailways) or Coralville (for Megabus) you'll often find more buses and cheaper fares between those cities and Chicago. The bus stop in Cedar Rapids is at the airport so you'd likely have to get a ride from there anyhow.