I have a 2003 Electra Glide Ultra Classic, and I think it's a great bike. Definitely a good year for the TC, and I like that 100th anniversary badge.
Taking into account everything Ron 750 said, and assuming correct answers, I think you paid a fair price.
I believe Ron was referring to the cam drive, not the final drive. The cam chain tensioners were a weak spot on those bikes. Many owners converted the cam drive to gears to eliminate the problems.
Oh OK is that an expensive part if not and what does it take to change it over? I'm new to harley and the only thing I did to my old bikes was change the oil and I'm sure it will be better on my pocket to learn how to work on it myself.