I have a 2004 Mazda RX-8, and have a P0661 engine light code. The estimate I was quoted by a local (non-Mazda dealer) repair shop to replace the solenoid after this error code was much higher than I expected. Have repair shop and parts prices really gone up this much?

$850 total:
$300 for the solenoid and $550 for labor.

I have to pay $200 for the diagnostic if I don't follow through with the repair, but they will credit that toward the $850 if I get it done. Affordable Tire and Brake in Portland, Oregon for what it's worth. They were always the only place that wouldn't flood my rotary engine when I took it in there for repairs so I have been going to them for 18 years before this with reasonable rates, but are these repair estimates reasonable?