All are expensive and must be done right to have value and a car worth showing. You cannot afford to do all three things to any one car today, even if the car is given to you. Let the first or second owner take his loss. The cost of labor and materials continue to escalate while collector car prices are flat. The less of a certain car made, generally speaking, the more it is worth.
Beauty equals bucks.
Apart from rarity, what counts is distinctive styling, how desirable the cars were when new, quality, and any special merit within the context of the automobile enthusiast community. The 124S gains a point to a 0 overall score. It's certainly beautiful. I guess they were desirable, inasmuch as it lasted second longest of all Fiats in this marketplace. When the top goes down, the price goes up.