If you are reasonably handy, its worth considering doing it yourself. I found this site very helpful. They sell spares for most domestic machines, and have videos showing you how to do the replacement of them.http://www.espares.co.uk/browse/at1085/washing-machines
In the past I've replaced a pump on a washing machine, a heater, a door catch, and a 'simmerstat' on our cooker, and a soap dispenser on a dishwasher. None of them turned out to be very difficult and it did wonders for my domestic credibility.
Obviously there are faults which are not easy to do at home, but if it's a popular make and you can identify the bit that's gone wrong it's probably worth a look before you get a repair man in. However honest they are, they have a living to make and are likely to be expensive.