Depends on your location, what type of paint and primer you will be using, and WHO will be laying the paint. Since there weren't alot of details given I am going to asume you are looking at just droping it off and saying paint it, so this is kinda an avarage for around here:
Paint and materials: $1500 - $3000
Labor for paint work: $1000-$2000
Labor for Prep work (sanding, ect.): $1000-$2000
You would also add a significant amout to this by having your doorjams, inner fenders, engine comartment, ect painted to match too. So roughly you're looking at $3500-$7000. And might I advise... DON'T take it to MACCO, caus eyou get what you pay for.
Now you may be able to save yourself some labor costs by having the truck prepped and ready for primer and paint when you bring it in.