One thing I really like in Norway was the speed limit, which is at max 70 km/h – often even lower at 50 km/h or 40 km/h. It gives you a lot of time to enjoy the surrounding. Also, due to the curvy roads it is not possible to drive faster in the first place. Keep this in mind when planning our road trip and destinations in Norway.
In order to finance the whole infrastructure in Norway, there are a lot of toll stations around. Some needs to be paid in cash some are automatically over the license plate or dongle in our rented car. It is different from station to station what to pay, for that reason I can not give you an exact number. But here a rough number, for driving around 3 weeks in the south of Norway we paid around 150 Euros for toll on top of the cost for the rental car and petrol.