Pat made good points. They should look at your car and tell you what they can/can't remove, repair. They should be able to do as much or little as you desire.
Is your paint just in need of refreshing and protection? If so, some reading could save you $100. Claybar, ploish, protectant, wax are all easy to do.
Do you have swirls, marring, scratches? Then you want a dual action or rotary. Ask them what type of products they use. Some people don't like removing any clear so they use products with alot of oils or fillers. They hide they imperfections but you eventually was that off and your paint looks bad again.
A good shop will look at your paint before AND after with a halogen or high power light to show all the imperfections.
Here is Charles' site with some great info:
http://melncal.com/detailing/