How much should I charge for making a web site?

the posts on this thread have all been a really interesting read. Its usfull to find out what others think, i've always done roughly the same let the client make the price only trouble with doing that too much/all the time is somtimes you cant loose focus of what somthing is really worth and before you know it your being ripped off and dont even know it. So thanks all for good info should help me in the future