Hello,
Nice project covering around 600 km and then some! The answer isn’t straightforward because there are quite a few ferry crossings with different operators—some have even become free. I’d suggest checking the Norwegian websites directly, as they’re often bilingual (Norwegian/English), and using Google Translate, which works well.
For example, here’s a site:
https://www.fergeruter.info/county/nordlandJust a heads-up: if you’re planning to go in the summer, expect long waits due to high traffic. Make sure to factor that into your schedule, along with finding overnight spots.
If you get an Autopass badge or something similar, you’ll qualify for discounts on the paid crossings.
The total cost of ferries will depend on the length of your camper van. For us, with a 6-meter van, it wasn’t too expensive (4 times route 17). The idea that ferries will break the bank is a bit of a myth—though many roads in Norway are toll roads, so keep that in mind too.
You can also check out the "Statens Vegvesen" site:
https://www.vegvesen.no/, which is really well done for all road info and real-time updates (or the app: *Vegvesentrafikk*). It has all the ferry details you’ll need.
Safe travels!