I need advise as far as which route I should go.. I have a 2005 Ford Mustang GT (V8) with just over 60K miles (manual trans). A couple weeks ago, I started to hear a clanking sound in my engine. I brought it in for immediate expection. The mechanic opened up the top left side of the engine and discovered one of the bearings was grinded down (cam-shaft/lifter/rocker arm damaged) and recommended to replace the cam-shaft, all the rocker arms and all the lifters on both sides (both cam-shafts) to start fresh (rather than just one side of the engine.) He quoted me at $1900 for the job. He expressed that this is a rare problem to have for a car with low miles, and may have been do to the cam-shaft being lifted from racing or racing up the rpm's (I don't do either).

My questions:
1) What may have caused this?
2) Is this the right course of action for such a problem?
3) What are the chances of this happening again once fixed?
4) Would it be better to fix or swap for a used engine that never had this issue?
5) Is this worth fixing and keeping (I love this car), or is it wiser to trade it in at a dealership for a newer car?
6) Has anyone had any similar issues?

Let me know...
Thank You,
Ben