That does seem a bit steep. I am a sparky in the south and to do that job it would be a days work including changing the consumer unit, an electrical installation certificate and because you can't clarify that the installtion is ok a periodic inspection report is required. (This i have only just found out from my registered body).
Cost - £250 Labour + £120 for Parts + 300 for testing. Its not just as easy as popping one out and putting one in anymore. On top of that you would have the bonding and that would be dependant on location. Hope this helps
Steve Rayner
August 2007