It depends on the Alfa Romeo. A 159 costs about £23000 ($36000). A Giulietta costs about £20000 ($31000). A MiTo costs about £13000 ($20000). The price may very on the dealer and the optional...
Brand new about 218,310 US dollars. or $ 109,155 pounds
It depends on the cut, carat, clarity and colour, variations in those categories.
5 cents
Depends on where you live and the condition of the polecat.