I had to go to Sverige for a wedding last July and paid ~1200 RT (MSP-AMS-CPH). My mom flew on Icelandair and paid a few hundred less. I would have done the same, but I wanted the NW EQM's. If you have no NW status, why do you care what airline you fly?

Another thing to look at is finding the cheapest flight (on any airline) to London and then flying a LCA to your final destination.