Most platers use a "lot" charge. You may ask them how many you can do in a lot and get other members to go in on a group buy.
I would also shop other places in other states. Some states really frown on plating and make it all but prohibitive. Also contacting a machine shop in your area that sends out parts for plating and maybe get in on one of their lots. I believe the finish you want comes from electroless nickel plating. This is a place in WI that the shops in my area use often
https://www.pioneermetal.com/. Hope this helps