I don't think the 348 will achieve the classic or collector status of a 308 QV or 328. Ferrari's less impressive cars (330's, 308GT4s, Mondials and 400s) can be considered classics, but are not the ones lusted after. The problem with the 348 is 3-fold: it had only had a marginal performance improvement over the 328 it replaced, every press article ever written noted handling and high-speed stability issues (even after the 92 re-work) and there was note significant public event to make the cars memorable. The were below the performance of comparable 911's and Corvettes of the same years. It is very hard to eliminate a reputation and hence why a nice low mileage 328 sells for more than a comparable 348. The 308 has the advantage of Magnum PI. The 365GTB4 Daytona and Testarossa have the advantage Miami Vice. The F355 could be questionable too. They held their resale well until only a couple of years ago. They were quite a step up in power, handling and performance with none of the noted issues of the model they replaced. Now that they are growing in age and mileage they are show some real issues. The valve guide issues and melting exhaust manifolds are the primary drivers for pushing early 355's into the $60K's. Without these problems, F360s are still holding well.
Oxford Pocket Dictionary definition: CLASSIC = of acknowledged excellence (= 348). I added the bracketed part at the end.
I think your point about China, India etc. is important. Their economies will grow and it will put a demand on all things of value and will therefore drive up the price, not only of Ferraris, but of all things that are in demand with a limited supply. I think that the price for a 348 won't change much over the next several years. I'm hoping that it will start to increase after that beyond the rate of inflation.