You might want to take a look at my Norway trip report which includes Oslo and Bergen; click on my name to find it. I mention some of the restaurants we frequented.

"Reasonable" is more likely than "inexpensive", relatively speaking. The cheaper the restaurant, the more expensive compared to US prices. Thus an Indian single plate meal that would cost less than $10 in the States, will cost $15+ in Norway.

Good luck with inexpensive.

Peppe's Pizza (which was pretty good) set me back 50+ bucks for a pizza and a beer in Bergen.

Whoa...looks like I'm gonna lose weight on this trip (or eat candy and gain weight)
Thanx for suggestions

The fried fish at the Fish Market in Bergen is as fresh as it gets. I wouldn't call if fine dining but the fish is good. It ran about $20 in 2007.

Also in Bergen, I had fish soup (in a very large bowl) for about $25 at Bryggeloftet & Stuene. The atmosphere was very Norwegian and I loved the soup. It is located in the picturesque area near the fish market. Norway is not a prime agriculture region so food is expensive. Fill up at your hotel's breakfast buffet.

Bring a basket of Kroner when you go to Norway. If you drink bring the max from duty free. Avoid Harbor Acker Brygge, a really overpriced area in an already overpriced city.

If you search, there is an early Oslo post with suggestions for "inexpensive" dining, mostly in ethnic restaurants.

My experience was the same as previous mentioned. We sought out recommended pizza chain for <US$20 per person meal in Oslo. Even looked at fast food as an alternative. We tried to picnic from the grocery, as we often do when traveling, and found our costs almost as high. Norway is the first place I've visited where basic bread seemed expensive.

We did intentionally stay at a hotel that Tripadvisor reviews confirmed had a substantial breakfast buffet. Unfortunately, we don't usually eat big meals, especially when going out in the heat in the summer, so we didn't eat as much as some others did.