I had a satin finish Model 60 "converted" to a high bright finish (polish) by S&W Performance Center and I was charged $200 +$14 for shipping. It came back with a real mirror finish. You might give S&W a call, they will quote you on the phone. HTH
Follow this link and scroll down. There is a good thread on polishing SS. Might save you some money. 500 Magnum Nut is a very good gun smith that helps us all. Read his post and you will learn. Don