Oh that's right.. BI/NHH are for business... NTNU is one of Norway's foremost science universities (it's in Trondheim which is about ~ 10 hours from Oslo)
Ive heard amazing things about that school. Can't remember if it was public or private so dunno if free or not.
As for living expenses... Well it's the most expensive country in the world.
Cost of living is generally 50-60% higher than the US but the overall cost of living in Oslo isn't THAT much higher than in NYC as the rent isn't as ridiculous and other cities. Trondheim will be cheaper than Oslo too.
the part where you'll notice price difference the most is food and ESPECIALLY alcohol. A beer is easily $15.. a bottle of vodka in the store is $50-ish and a shot at the bar is $10-12
Also cars, a Chevrolet Camaro for instance is like $250,000 but that won't be a problem for you as a student
Estimated living costs:
~ $500-600 on food (I eat for $1000 a month, but that's on my mum's bill and she buys expensive food and never buys anything in bulk)
~ $500 on rent (should include electricity internet and satellite TV, this is for a 20m² studio apartment or 30-35m² shared with 1 person)
~ $100 per night out
~ $200 on misc (travel card, mobile phone subscription, some clothes here and there, cinema tickets...)
we're talking ~ $1500-ish per month but bear in mind that almost any job will pay you $25 an hour. My part time job in a factory pays $35/hour base rate, and adds up to $80 PER HOUR during weekends/bank holidays at night ^^
Doesnt seem expensive at all compared to u.s....