The Alfa's are great, but that particular one doesn't have a sportpack. The non sportpack V6 handles like a soggy sofa.
I have owned 2 V6 156's (sportpack versions) and the fuel consumption was similar to the Coupe, but they are quite a bit slower, and need revving to go fast.
If that car needs a clutch it will be about £700, and if it needs a waterpump it will need a cambelt job at the same time. I couldn't see on the advert any mention of them being done.
They are a bit like the Coupe in that if you get a bad one it will cost a fortune, but a good one will generally be reliable.
I do love my Alfa's.