Hotel accommodation in Norway doesn't come cheap, but if you do your homework; there's no need to break the bank.
Hotels in Norway are invariably clean, comfortable and well-appointed. However, few are likely to win any architecture prizes; so think concrete and glass rather than the charming weatherboard houses that decorate most postcards. Room prices typically include a generous buffet breakfast; which is more than enough to set you up for the day.
In 2006 Oslo made it to the top spot as the world's most expensive city; stealing the crown from Tokyo. However, substantial discounts can be had if you time your visit for the summer months or take advantage of promotional weekend rates(ask the Tourist Office about discounts available with a combined Oslo Package and Oslo Card).
Cheaper still, and a great way to get a better feel for Norwegian culture, is to book into a local pension( pensjonat) or a private room in someone's house. You'll also be able to pick the owner's brains about what to see and do in the locality. Expect to pay somewhere between 200-300Kr.
Outside the cities there are plenty of other accommodation options, many of which will get you closer to nature. Norway has over 500 official campsites, most of which are well appointed with facilities, often including wood cabins which can be hired out for les than 150Kr.
Many popular trekking regions have networks of well-stocked cabins, where you simply turn up and leave the required amount on departure. For further information contact the extremely amiable Norwegian Tourist Board.