Expensive. That is my opinion. You pay a lot of money because it is a tourist attraction. The only thing that is cheap there is food from fast food places. The valley of the waves is also a decent price (about R 120 - that is if I remember correctly) for a full day, but it only includes the wave pool and slides.
Sun City, South Africa?
You really need to be more specific with your questions - we can't possibly list all available activities and their cost. However, their web page could probably give you some insight about activities and entertainment:
what is the price for quad biking????