Even for those who try to do the North in a few weeks or a month there are some fixed costs. Transportation costs won't vary much. The big part is getting there & coming back. Those with time don't ad...
After a few years of not being part of it I see K2 Aviation has an offer in the tour saver book. Just one tour & it is 20% off, not a 2 for 1, but it is a great tour with the glacier landing.