that depends on your needs I would think...
Catia and UniGraphics can cost well over $100,000 when you add on all the possible
additions to it....
for the home user looking to learn, Poswer, Bryce, and a number of other lower end lower priced programs are there, and they can produce quality 3D with skill learned over a period of time making use of them...
sooo

ZBrush @ 399.00 Euro, which is the same as the US$ pretty much is not to high a price for the program by far....
One of my fav's right up there with DangeRuss in my opinion, though DangeRuss is tops in my opinion...
Stevie-rae Townsend: http://209.132.69.82/showcase/getthumbs.shtml?0_Modeling&includeprefix=fury_&linkall
ZBrush is a extreamly fantastic 3D application which could very well call for double the price and still sell just as much as it does now. Yet they keep it in the upper low to lower medium price range because they are happy with the ROI in producing it and the community that has grown from it's use..