I painted my own car and the materials alone cost $1000. All paints are not created equal.
A good repaint including fixing small dents or rust spots, removing (not masking) all trim pieces, block sanding the surface flat, basecoat/clear with quality materials, clear sanding and polishing will cost about $3000. A color change requiring trunk and hood underside, door jams etc would be even more.
Less than that means lower grade materials, less time in the prep, single stage paint, orange peel in the final product, no dent repairs, overspray on the trim, or some other combination of shortcuts.
Earl Schieb: "Any car, any color, one ninety-nine ninety-nine". Peels off in 2 years.