I wish I was familiar with the prices in Alberto K, but unfortunately I am not. You are located in the middle of the city and can easily walk to restaurants in the immediate area. I am pretty sure the prices will be sky-high as well, but recently a new (actually it was a re-opening) restaurant opened in Tivoli, which is literally across the street from your hotel. The restaurant is called Nimb and you can choose to visit Tivoli as well (but pls note that you'll have to pay an entrance fee here) or if you are not inclined to visit Tivoli, you can enter from the street. It is VERY close to Radisson. See their web site here: http://www.nimb.dk/
Tivoli of course has a nice variety of restaurants, but they are often somewhat overpriced and not really gourmet.
For your more laid back dinner, I recommend Spicylicious at Istedgade. It is a good Thai-restaurant with a modern and trendy interior. It is a bit more expensive than the other Thai-places in the same area. But still relatively cheap.
When you walk out your hotel, you turn right and walk to the intersection, which you cross and turn right again. In the big intersection, after passin by Central Station, you turn left and walk next to a grey, large building (Hotel Astoria). The first street to your right is Istedgade. Turn down there and walk almost to the intersection. Just before the intersection on Istedgade, you find Spicylicious. You will pass a lot of hotels and some what seedy establishments (bodegas, strip-joints and sex-shops) but don't be fooled or afraid. After a little while it all becomes much nicer ;-) Istedgade is one of the main streets in the neighborhood called Vesterbro, and has many great shops, lots of people of all nationalities, lots of young families and students. If the weather is nice, the whole street is buzzing.
I recommend that you book a table beforehand in Spicylicious, they are often pretty full. Here are their webpage: www.restaurantspicylicious.dk/uk/index.php
If they are full that day, pass by them and turn lef in the intersection nearby. Walk down to the cobbled street and turn right. After a few meters, you will happen upon another good Thai-place called Thai-Esan. Cheaper than Spicylicious.
You can also head back up Istedgade towards the Central Station and turn right on Lille Istedgade. Here you will find a tiny Thai-place called Thai-Esan as well.
Vesterbrogade, where your hotel is located, has several Chinese buffet style restaurants as well as a large Turkish buffet style place. From your hotel you head down Vesterbrogade, away from Tivoli and Central Station. If you walk even further down Vesterbrogade, there is also a place called Café André Citroën serving café-style burgers, soups, salads, main courses etc. Also nice coffee here. Next to André Citroën you will find a popular Vietnamese restaurant.
As I said, you can walk to all those places, and they are all in your immediate neighborhood.
Hope this helped :-)