I've been told that only ivory and pearl stay in high demand over time - I don't think ebony is quite there. In fact, I personally find ebony pretty boring as far as woods are concerned. I think a fine burl, ironwood, or rosewood, looks ten times better, but that's just me.
Investment should mean that you have a reasonable expectation to be able to turn around and sell the knife and make a reasonable profit. If what you want is more a family treasure, then I would call that heirloom quality. Not exactly the same thing.
I personally believe that the *vast* majority of knives, even from ABS MS, loose value over time. I have no experience in fancy folders, so my opinion is purely limited to fixed blades.
This is based on limited experience trying to sell knives, or buying top quality knives at ridiculous prices.
The knives where I made a profit were early, simple knives, typically in the $100 - $400 range, from people who went on to become top names. Of course, it's hard to guess that ahead of time - quality is a necessary but not a sufficient condition to achieve "knife stardom".
If I were to trully invest money in a knife collection, I would seek good quality, simple and reasonably priced knives from makers with great potential - Dan Farr, Terry Primos, Jason Knight, Nick Wheeler, etc. Even those guys fetch fairly high prices from retailers (sometimes very high), so I would endeavor to buy directly from them.
One thing to take into account is the horizon. For a short term, most top name makers are fairly safe investments, but for the long term, it's hard to see who will have the following of a Moran or a Loveless.
Finally, we all need to look at the big names out there and assess the quality of their work. There are makers whose work's value is based on a long history of quality and leadership, and there are others whose value are not supported by the quality of their work.
