Quoted from CoolCatPinball:Unfortunately the cost varies GREATLY. If you have someone locally, who isn't adverse to doing small jobs, it can be quite reasonable. If you need to ship parts back and forth, it can get expensive. On the high end you could spend almost $400. On the low end $150. My local guys do amazing work for $150 as long as I pick a color they have in stock, or bring them the powder of my choosing.
Mine is usually $2-300 but I also do shooter housing, hinges, cd, loli rails, and sometimes aprons and habitrails.