You know Dave, I hate to argue because you have a heck of a lot more experience than me, but I suggest going cheaper ($80-150). This is because it is such a hard knife to learn, and many people get frustrated and sell theirs. Imagine dropping $300-400 on a nice one and having to sell it. They aren't popular, so not many are going to jump at it. But what do I know.
jason, i really see where you are coming from here, but i have to disagree. More often than not, i dissuade people from buying usuba for similar reasons to what you stated. But if you do buy one, and you go with a cheap/bad one, the problems you often find make the blade much more difficult to use, sharpen, care for, and learn on. That alone can make people give up on learning the knife. You dont have to spend $400-500 on one, but i would say somewhere around $150-200 is the least i would ever spend on one. Twisting, bending, bad grinds, etc. show up big time in these knives due to their relatively thin nature.