You can bet it's thousands of US dollars, if not tens of thousands. Just a single seat of Solidworks is $4000 without any extras. Believe it or not, that was actually crazy cheap for parametric CAD back when Solidworks started becoming popular ~15 years ago.
As much as people give Solidworks flak, it actually is really, really good software for what it does, and it does a lot of different things. There are other pieces of software that can match or exceed it in single matters, but very few can do all the things it does. While it's not cheap by an means, it fills a role at which little else comes close.
In other words, it may be $4000, but it does what would take four or five $1000 (plus training) pieces of software to do.
As a near-daily Solidworks user, I totally agree. The problem in my mind is just that the barrier to entry is so high due to cost that it prevents the kind of open collaboration on mechanical design that's been possible for years in software and electronic hardware. Just like 3D printers, prices will come down to better serve hobbyists and individuals -- it's just a matter of time.
Solidworks is a great 3d modeller software. It's a pleasure to do most things in, and gets out of the way when you want it to.
The only modeller I like more for certain operations is OpenSCAD, but that's because I can understand the math operations in printed pieces in complex curves.
The one program I want to see die a firey death in source-code hell is ProEngineer, now called Creo(sote). It is patently user-unfriendly, and requires so much PITA setup to even do things like regular polygons. "Oh, you want to fillet? You better do it in the right order, or the last fillet _WILL_ fail!"
