Was only joking about the mega bucks.... or at least I hope so.
As for the sensor... Had a weird problem a year or so back on the wife's car, a Corsa. She called me to say, the power steering had packed in, the speedo wasn't working and brakes seemed heavy.
That proved to be an ABS sensor on the wheel. I questioned this with the garage, as her little Corsa doesn't have ABS. But it seems they fit these ABS sensors as they are a good way of feeding speed and slip of the wheel to the cars "brain". In our case, was a way of driving the speedo, the assistance for power steering and brakes.
A Vauxhall dealer dealt with it, and I was surprised how little it cost to resolve. Biggest cost being dealership hourly rate.
Hope it proves to be something like this for you....