I agree with Bob. There are several factors to consider. Is it the original paint that is going bad, or have these areas been spotted in the past and something has gone wrong? Plus, the color of that car is likely to fade in the sun. If you "spot" fresh paint in the bad areas then re-clear coat the whole panel, the new paint will be a darker richer shade than the rest of the car. It the car has been repainted already, and there are problems, then you may be dealing with a much more drastic situation that may require stripping the whole car to get rid of whatever is causing the paint to not adhere.
I would say if you are prepared to spend as much as $3,500 then there is no doubt that car can be returned to a "show room" look. However, if it has been garage kept with minimal to no fading, you may be able to have it spotted then cleared on the damaged panels for $500 or less. Also, it this is stock paint, what you are seeing may be getting ready to happen everywhere. In other words, you run the risk of spotting it in every six months somewhere different. Thus, it makes the most sense to strip and paint the whole car.
