Re: 147 repair costs
When you say "Sump washer" do you mean the sump gasket, or the sump plug washer?
If the latter then, yes, WTF?!??! This part will cost £0.25 and could be changed in about 2 minutes. They may be suggesting that you drain the oil completely before changing the washer in which case (assuming no oil is leaking) I wouldn't bother putting the washer back in until you go for a service.
How many miles has your Alfa done? You should really be going for the cam belt/tensioner/variator change at about 36,000miles.