Considering the external cabinet will have decals over most of it, except the headbox, I'd be inclined to finish the job myself. If you have already prepped the cabinet and laid down the primer, and masked it, then you are 90% done. It should not take longer than 20 minutes to repaint the cabinet in the base coat. You have done the hard work already. You don't need a booth for this kind of work. Do it outside and in the shade.
