As far as cost, I won't discuss that here. There are too many variables to consider, so it would be best to call so I can get the information needed to do an estimate.
Some of the failures you describe are aftermarket, some factory. Care to comment which you see more of?
Regarding cost, for the sake of those who will utilize the thread I was hoping for a rough ballpark. I'm guessing it would run as much or more than the cost of a Hughes shaft system ($760)?
No worries if you prefer not to say.