You happen to own a copy of a few dozen 308GT4 kits ever produced by an enthusiastic individual, and it looks pretty good for a garage kit.
I can't afford anything more than 10,000 yen for a 1/24 scale kit (at least for now), but I'd love to have it, too. Apparently the next kit will be Maserati Khamsin, which is just as obscure as the 308GTB.