Andy wrote:You'll need to contact them for the latest price. We had a trade price with GTPE, and I've not worked with them for 2 1/2 years now, so any reference I have will be out of date.

Here is a quote I got from Derek @ Aptec in February this year (2020), admittedly to a UK address:

"the exhaust bridges are always relieved to allow for expansion, the bridge would otherwise expand into the cylinder and wear a flat on the piston rings.
That said it does look like this is worn to some extent.
The cost of the re-plate and hone is £137.92, return carriage £11.50 prices are plus Vat and turnaround is generally 10 working days."