+1 to that ....... check out google and make a few calls before committing to that kind of bill ... Here are a coupla links ..... they may be able to repair it for a lot less than 800 quid .. didn't know you drove a Roller ...... ... ........... ....

http://www.carelectricsuk.com/services.htm

http://www.yell.com/s/car+electrics-suffolk.html