trailing and radius arm bushes and rubbers

I have a Ford Focus 2009. It has just had a service from Ford main dealership they said the nsr trailing arm bush is debonded and both radius arm rubbers debonded. Cost £376.12 to fix!!! I know the bushes etc are only about £5 to £7. Does anyone know if a smaller garage could do this as they say it must be a Main dealership as they have the equipment!