It's a good price if the Aires isn't damaged.
Understand that a wind vane isn't the same as an autopilot. An autopilot will guide your boat whether there's wind or not, while a windvane requires a substantial amount of wind to do its thing.
That said, I love my Aires. It's guided me over many sea miles and, the harder it blows, the more the Aires likes it (unlike autopilots which often are overwhelmed by big seas).
Windvanes don't use electricity, don't talk back, work 24/7 happily, and don't drink the beer. Great things to have aboard on ocean passages. Not much use for short trips.