If I was from Norway or Sweden I would demand the national grid to massively invest into the transmission lines to make all the electricity produced in the country actually usable anywhere in the country. Basically work to get rid of these pricing regions within the country. This is how the network here in Finland works
Also why they are now talking about adding new lines from south of Finland to Sweden (also mentioned in the article) so the electricity produced in north Sweden can be sold to south Sweden through Finland as the national grid of Sweden just can't get it done.
edit:
You can go to https://www.nordpoolgroup.com/en/Market-data1/Dayahead/Area-... to check the day ahead prices in different price regions.