Note that unless you have a toll package, you’ll pay an administrative/ convenience fee (which may work out to be a better deal anyway). Most companies charge a flat daily fee, but some charge by the occurrences.
A couple years ago we rented a budget (not Budget) car rental in Orlando. They were doing roadwork which forced us on one of those toll roads that charges 75c - in coins only - to enter and exit. Of course we didn’t have this and the rental company charged us a $20 daily toll fee, $1.50 for the tolls and $70 ($35 each) for toll violation (imposed by the rental company). Which was more than we otherwise paid for the rental!