"Collectability" is a subject that has been covered here many times.
For a guitar to become a collector's item, it has to be at least one of the following:
- Actually owned and/or used by someone famous. This applies only to specific instruments (like Vai's EVO), and has to be documented by serial numbers, photos and other support info.
- Rare. That means produced in small numbers, or completely unique one-off custom or prototype instruments, unmodified from their original factory state.
- Desirable. Players or collectors have to actually want it.
If you ask me (and i'm not a collector at all), a guitar would need to fit at least two of those criteria for it to appreciate in value over time.
A guitar can be artist-played and rare, but if nobody is interested, it's not really much of a collector's item. Similarly, if the market is flooded with them, the economics of supply and demand take over... if everyone who wants one can get one, the price and cachet won't increase.
A lot of Vai's one-off guitars and prototypes have been auctioned off for high prices because they fit all three. However, their worth on the free market is questionable... Neville or Red Lace might never be sold again for such high prices. Chrome Boys have held their value rather well, especially ones in better condition.
I really doubt the JS2000CG will increase in value very much, if at all. Few guitars do. Most just become "old" and "used" as opposed to "vintage".