1. Depends on the Type of the Paint, the color etc. Can Range from Minimum 2000 to Max even 8,000 also the type of car etc.
2. Formalities include - Traffic Police Approval incase you wish to change the color & if its the same color i dont think so. But I guess a approval is need for the company that will paint your car.
3. I personally doubt if any company paints a car real good as in as good as manufacturer. Check in Industrail Area all have different rates. I suggest you get a well done heat painting for good gloss & shine

good Luck