Hope this helps you in deciding complete exterior paint job, or partial trim only exterior paint job, saving painting costs when you can, from your local area painting contractor.
You'll need a large compressor, not just the typical 20 gallon variety most of us have. This is a 60 gallon, vertical compressor with typically a 5+ hp motor. Then you'll need a decent paint gun (possibly 2; one for primer and one for color) which again is an expense. Then there's the question of where you'll paint the car. Renting a paint booth is best, but can be expensive and hard to find. You can always seal up your garage or shoot out in the wetted down driveway, but you'll inevitably get dirt and moisture into the paint.
THE BRUSHWORK. Depending on the art movement and personal peculiarities of the artist, the brushwork can range from delicate and almost invisible to rough and plastic.
Also, when checking the paint, be realistic and don't ignore areas just for the sake of convenience. It will cost you more in time and money later. Typically if one area of the paint is cracked or peeling, then the paint on the entire car is suspect. Maybe the rest of the car just hasn't quite reached that point of decay, but it will shortly. So if you only fix areas that look bad, you'll likely find that you wasted a paint job when the other areas start to crack or peel in a year or two.
Water-thinned interior paints are calcimine, casein, resin-emulsion, and gloss water paints. Calcimine consists of powdered whiting and clay mixed with an animal-glue binder and a preservative. It cannot be recoated, but can be easily washed off before redecorating.
Selecting a Shop. You should always get quotes from at least 2-3 different shops near you. This will give you a chance to not only compare prices, but to also check out the quality of work each shop has done. Ask to see cars they've just painted. Look for orange peel or excessive overspray. Do they mostly do insurance work or do they paint entire cars also? What types of cars are they working on? A shop that sprays nothing but old beaters probably doesn't inspire as much confidence as one that does insurance work for the local Lexus or Mercedes dealer.
Painting ceiling does not require premium paint. You can use flat $15 to $20 ceiling paint. I use Sherwin Williams PRO-MAR 200. Painting ceiling requires a lot of physical work and plenty of drop cloths. If you are not up for the challenge or have very high ceilings contacted a professional will prove to be a smart move.