I wouldnt even dream of spending £15k on an Alfa, and I should know as I had one, I had a 147 2.0 fully loaded, it handled better than my car before it Audi A2, but was nothing on any of my subsequent cars, or other decent cars I have driven. I would be looking as Fox says no more than £5k.
As for reliability thats a load of tosh, I had no issues with mine and numerous owners at alfaowners (I think that was the community I was part of, 'twas a whiles ago) didnt either. The only thing I can say bad again them is they are litterally made of tin foil and wet Tescos value tissue paper, dont even dream of it standing upto a crash, mine looked like I had been in a serious head on collision, when I litterally tapped a car in from at 5-10mph (yes that slow, was 2 meters from a turning I had just turned out of). Which brings me only the second niggle with the car, the brakes are rubbish to say the least, dont even think of making emergency stops in time, the brakes are fluffy (not spongy that would mean you got some actually brake feel) and hideous.
Other than those niggles, oh and the fact it drinks oil at 1L per 2k miles it wasnt bad a car, wouldnt buy again though, as the depreciation hit me hardest, £3k lost in in barely 1 year.