I have one.
I can say it is an absolute pig of a thing to set up.
My advice to you would be to watch the CD at least three times before trying to set up and to follow the instructions down to the letter.
Once it is set up it is a great bit of kit, you can make all sorts of box joints with it, 2 small at each end with a large one in the middle, you can create some lovely looking stuff with it.
Personally I think it is worth the money, others will think differently so it all depends on how much you will use it.