Miles: Don't be alarmed over the high numbers people are throwing at you
The money you need really depends on a lot of things. Some of them already mentioned here. Here are some of the factors you need to caculate:
1: Food! Eating at the consite is rather expensive. There are various food options. The cheapest is the burgers from the bar. They cost 9 eur but they were quite HUGE last year. In the morning/evening the hotel usually offers some kind of brunch buffet and in the evening a la carte and that is very expensive as well is the buffet. What you CAN do is to shop food at the local lidl or aldi just down the hill. In your room you have a very small frigde where you can store some food for fx. breakfest.
2: Drink! I don't know how much you drink but the booze cost as well. I won't say its cheap but it's not overly costy as well. Again a way of saving money is to buy some bottels down town and mix in your room.
3: Deales den! Here you can spend a lot of money or you can spend nothing. I must say it hard not to spend money in the dealers den because of all the nice stuff thats for sale, but yet again its really up to you how much you wanna spend.
Last year i brought 2000 DKR and that was enough. I even bought a good few things in the dealers den. I would say bring at least 1500 or better lets say 2000 kr with you. Better to have a little extra than a little too little. If you bring 5000 NKR you should have more than enough to both buy/drink/eat the whole con.