Am replacing the chainplates on my boat- 8 in total. Cost Stainless metal (316) $25.00 each- cut to size, drilling the holes and welding spacers on the end. $0.00 - exchanged some wood work for the labor. Brought the stainless at http://www.pennstainless.com/
they will custom cut!
Installing- about $30.00 for all new nuts and bolts, and another $40.00 for bedding material.
Whatever you do DO NOT let the boatyard do this project, it's not a big deal, they wanted to charge me $200.00 per piece uninstalled.! Unless hey give you a reasonable price. But you will definitely save a lot of money by DYI.
And I'm doing them 2x a time while the mast is up! no big deal here!