W140 ABS warning light / relucter ring

[Bumble]

Hit a bump in the road and my ABS warning light came on , the steering often goes heavy now and the ABS light is mostly on all the time. A Merc specialist says the Relucter ring on the driveshaft has split and the whole unit needs to be replaced as this ring is a fixture to the shaft - £700 + vat - OUCH !!! Got to get a second opinion. has anyone encountered anything similar - Gutted of Walsall !