I absolutely agree that $75 is too much for them to be charging to re-program your existing usa-spec. I think it should be closer to $40 for that service. I wonder you can find a local stereo installer that might be able to offer the service a bit cheaper.
That said, I think it's very cool that they are even willing to provide that service at all. Really this is Apple fault for not being backward compatible with the protocol. They did the same thing when they dropped firewire charging and went usb only. In apples defence, they have maintained the same connector with the majority of the same connectivity across multiple products and lots of years, so I'm not picking on Apple, but it is still their fault.
Sorry if I am not very sympathetic, but I think usa-spec shouldn't be slammed for not being able to forecast Apple's future product interfaces and protocols.
In my case, I originally bought a second ipod nano 3 gen 8gb that stays in my car all the time except when I am reprogramming it.