After owning my HHKB Pro II for a few months, I can tell you it's definitely a boutique item, as Ripster has said. I find it worth the money because I know whether it's a year old, or 10, the key feel will stay the same (generally), the keys will stay stiffer than any switch, and I will always be able to adapt the port from from usb2.0 mini to whatever might crop up next. It's also uniform and compact layout means I can buy extensions if I miss any portion of the keyboard too much. Which is much harder than attempting to saw a keyboard in half, removing stuff I don't want. I was nervous about getting the petite layout, but I was glad I did. Every day for about a month I was almost "giddy" typing on it, because I found myself never having to leave the home row, and actually using keys I didn't use much before because of how out of the way they were (specifically the home/end pageup/pagedown keys). I now use these, just as much as I use my arrow keys if I can.
With that said, asking "is it worth it?" will give you mixed results. Obviously, I find it worth it, and a few others will too. Others feel it's just a glorified rubber dome, and while sturdy, provides little to no feedback - and can't imagine why anyone would buy them
Imagine that, Geekhackers with opinions.
Personally speaking, if I don't get exactly what I want, I end up regretting it until I do, it'll just keep bugging me in the back of my mind. So I took a leap, and the first couple days I was really contemplating why I dumped so much money on so little. Then it grew on me, and now I use my HHKB exclusively (sold my month old Filco and if there's any interested local buyers, I'll part with my G80 as well).