True, everything is expensive.. Unless you know how to avoid it. Basically you are able to live for free if you know how to. You're allowed to camp for free everywhere you want to as long as you're 100 meters or more away from a house where people live, and as long as you move your camp after 3 days when you're in sight of people. Moving it 3 inches is enough, the law doesn't say how far you need to move it. If you put up a camp in the woods it can stay through the summer, or even for years if you like it cold (We had 3 months with an average temperature of -25'C last winter..)
Go to the local butcher for meat instead of the local super market chain, and you get moose for less money than commersial meat. Or talk to a hunter, it's a lot of hunters up here. Not yet allowed to hunt with a bow and arrow, but if you live close to Sweeden it's no trouble. Fishing is free in some large lakes and along the coast. Talk to the local farm and you get vegetables very cheap. Woods are full of free berries, and peolpe are usually happy if you help them collect their garden fruits. Just call the doorbell and ask.
And yes, reindeer meat is easy to find. (My wife is Saami, so we usually have more than halv a reindeer in the freezer, bought or traded with family and friends in Finnmark). Buying it here in the southern parts of Norway is expensive though.
But yes, it is generally expensive up here.. That's why Norwegian tourists seem to go wild everywhere they are..
I guess the average hard working during the summer could easy save up 100 000,- NOK. 300 000,- is for the ones lucky to find a well paid job or two. Selling bows and other handwork might also be a good source of income, if you know where to sell it.