I've had 2 friends get macco paint jobs, one on a full size blazer for $800, and the other was a geo tracker for $350. We did all the prep work ourself.
Start by removing all the hardware: door handles, take the top compleatly off if you can, any seals or parts still attached to the body.
Sand down with progressivly higher sandpaper: 100, 200, 400 (the highest we used on one). 800 if needed. Don't go through the primer to baremetal, but if you start to see the primer thats not bad. your trying to take the shine off.
Blow of the dust and wipe down with paint thinner, or somekind of degreaser to clean it. it will also highlight any areas that are still shiny and need to be sanded down more. After that I have no real experiance.