The thing about Alfasuds is that 99% of them have been scrapped. Literally, there is probably only 1% of the entire production run left in good running condition. Most were scrapped 15-20 years ago. There are almost none left in Italy where they never sold that well anyway. The chances of finding a 1977 example that needs no work in between unlikely and zero, so whatever you buy be prepared to do some/quite a lot of work.
Definitely worth the expense though!
I don't know how many that are left but according to Tim's Alfasud webpage Tim's Alfasud Page
1017387 Alfasuds and sprints were build. If we spilt it up in models we got 715170 Alfasuds, 185665 ti's and 116552 Sprints.