Well, I'm not sure I can tell you how to go about buying a site, but I can tell you that overflow is the way to go! You really have to rough it (no showers, and porta-potties only) but it's the most fun place to stay. The on-grounds campground is way too crowded, and it gets annoying. But in overflow you usually have a lot of space to set up camp. Oh, and one other thing....the parties are AWESOME!!!