We recently used Domex for both our washing machine repair and a few weeks later dishwasher repair. Was very happy with the service and they were upfront about the cost of the initial investigation and the cost of the repair / parts.
Www.domex-uk.co.uk
Having used poor service men before, i liked the fact I am dealing with a company that provides guarantees for everything.
Depends on what the issue is, our washing machine had a broken door handle, that cost us around £100 including the part, the initial assessment and then another visit to replace the door handle. The dishwasher was more expensive as the parts to replace cost us £200. The actual work was less than £100.