I remember the advertisement very well because I suggested a fellow alfa fan to buy it! Most probably I found the car on "mobile.de" . I really cant say the price for sure, but say 20.000 Euros, about the double of a good street car. And it was Loubetīs original car!
Some more info in the french GTV Passion site:
http://www.gtvpassion.com/somm.htm