My A3 2.0 Fsi Sport (53 plate, 27k) suddenly cut out during the week, I had it toed to Audi and they've reported it being the EGR VALVE!! They've informed me it can break at anytime and will cost me £611. Is this an extreme amount or a true valuation to fix this type of problem? They've also said my computer will need reseting. Any advice would be helpful.

Many thanks