Alpine Vs SS is a no brainer. The key elements are (IMHO):
How will they be used? For me you cannot have one 'special' car. As soon as you drive it every day it loses a lot of its magic.
If your priority is for something a bit practical then a nice 4wd estate will trounce whatever cheap practical car you buy compared the enjoyment an SS will give you.
If your priority is the fun element then the enjoyment you get from the Morgan will more than making up for our somewhat adequate everyday steed.
I loved the occasion of my SS but sold it because it wasn't a convertible. It was the most dramatic car I have owned.
I won't bother answering the fuel question because I really don't know. I do now that my Aeros always gave between 22 and 30 Mpg - very much dependent on roof position as I always drove them one way
Other cars I own/have have owned that may be relevant to your situation? 996C4S, 996TurboS, E55AMG, E36M3, E46M3, Z3M ACS, F348GTS, F16M Scuderia Spider, BMW X6, GTC Speed. Oh and 3 other Morgan but regrettably no Alpinas
Hope that helps and good luck.
PS I haven't even mentioned depreciation
