If you're doing an organised overland tour, your drivers will very likely bring you immediately to a place where you can book some activities. They'll show you a video and then it's booking time. This all sounds good but the prices at this place are most of the time much higher that other places. The thing is that the drivers have to drive directly to the activitiescenter so the tourist won't be able to check the other offers. This tactic is used in many of the adventure towns in Africa but in Swakopmund the price difference was shokking.
ps: the picture is not the center i'm talking of, it's just a house in Swakopmund.
A good thing to do is waiting with the booking and wander around time a bit; If the company says you have to book immediately, just don't do it because they are probably ripping you off.
Swakopmund, on the weekend, has a fantastic market, where people come to sell their crafts. Be warned though, they are often items imported from Zimbabwe, and the people who are selling can be very difficult to deal with.