I would think twice about doing this, especially doing it yourself. $1100 sounds to me like 3-4 full days of work by someone who has already done this a time or two.
Pro: Looks better and right now looks like chit.
Con: More work than new rubrail by far.
Capping is going to require some good paint matching/applying skills. Do you have them?
May crack in the future, thus looking like chit again.
You will never be able to use a dock again without one or two trusted friends to keep the hull off of the dock.
Trusted friends may still stop paying attention, and then you are back to looking jacked up.