All those looking for a low cost solids package might want to look at ViaCAD.
http://punchcad.com/p-9-viacad-2d3d-v8.aspxIt’s a modeless, hybrid surface / solid modeler which allows for direct modeling, which means you don’t have to draw something, dimension it and then extrude. It is not parametric, but their is a history tree that allows you to go back and edit dimensions. The package has a really good export to STL which allows you to easily change and see subdivisions and facet count. It will also import and export all the main formats, but not Parasolids (SolidWorks).
The basic Mac / PC consumer version is $100, but is often available on special for less.
I have been using the Pro version for 10 plus years, and keep coming back to as I find it the most intuitive package available at a decent price.