Punting in the Nordic regions is a waste of time and money, you're far better off trying it on with the local women. Go on the likes of tinder as another punter mentioned SA or some other similar sugarbaby site. I'd get on them now pay extra on tinder/bumble to be able to move your location to Norway and start swiping, talking to women before your trip.
The prices in Oslo are 20 % higher for the same services if you visit girls from eastern Europe. If you want to meet a nice normal looking norwegian girl, you´ll be paying minimum £250 per hour.
If you´re unlucky and get caught by the police, the fine is £2000.
There is no point in coming to Norway if punting is the main objective.
Go skiing and see the fjords and northern lights. Do the punting elsewhere.