I was there in the '70's when K Mart had their give away sale. I worked at Mattel Toys in West LA (design engineer - first job out of college) and one of the model makers who I worked there told me to head over to K Mart after work before they were all sold out. I picked up three, the Alfa Monza, Alfa Spyder and the Fiat race car, $15 for each ($40 was my weekly grocery bill back then). I tried building one of the wire wheel assemblies (with mating spoke ferrules if I recall). I gave up in frustration, ended up re-gifting the Fiat to my brother and selling the two Alfa's to a co-worker.
Forty years and more modeling skills and free time later, I'd love to take another crack on one of these classic kits. Look's like one can pick up one of these Alfa's on eBay for $400-$600 which is not unreasonable for a large scale multimedia kit. The engineering/ molding/ fit are probably pretty crude by today's standards but based on finished builds I see on the web, they look pretty good (at least from 3 feet away!). Problem as always with big kits is where the heck do I put it!
Go for it and consider it a learning experience. Worse case you can put it back in the box and re-gift it or sell it!