Such a shame..... Although they sound like they're having you on.
Id get a 2nd opinion. If you're referring to the ECU, it certainly wont be £600. You could check the ABS rings yourself if needs be.
The belts are not quite as daunting to do as they seem (apparently) so if you're useful with spanners you could give it a go yourself or get one of the mobile mechanics on .org to help you out, they are very reasonable.
Whats wrong with the Inlet Manifold?
PS if you scrap it i'll shotgun some of your parts
