£140!!! Blimey ouch.
I thought £50 was about right. Managed to get my wheels done at a place next door to the Alfa dealer (they sorted it for me) and they only charged me £38. May not have been the same system, but they seemed to know what they were doing, and yes, they said they would 'overide' the official setting to give me 0.00 at the front.
I also run the pressure around 40psi front 39psi rear which seems to help. Since the alignment has been done, there is definitley less wear on the inside edge. The last continentals were replaced at 9600 miles, tread was fine on the outer/centre portion, it was the inside that was worn quite badly.
Always seems to be an issue with Alfas that I've had, my GT was particularly poor.