There are three versions of the program: Deluxe, Professional and Platinum. The Deluxe version has a list price of $130. It can design objects and create photo-realistic renderings, but it only handles Surfaces, not Solids, so it is missing some of the functionality of the Professional and Platinum versions. In terms of ability, the Professional version is comparable to AutoCAD while the Platinum version adds extra Mechanical and Architectural functions.
I can quickly design (or transcribe an existing design) to get up and running quickly. The user interface is largely consistent (there are some exceptions for some of the more unusual functions), but almost totally flexible (I can place tools under pretty much any drop-down menu and get to them via mouse or keyboard). If I want, I can switch over to an AutoCAD-compatible user interface as well as importing and exporting AutoCAD-compatible files, plus a couple dozen other file formats.
You can buy or subscribe to the software. If you buy, you can use it forever (so long as the operating system supports it).
If you are a programmer, you can write DLLs that can enhance the functionality. An SDK is available.
As with any CAD software, there is a steep learning curve. Get a tutorial for the 2D and 3D functions to get up and running as quickly as possible. Also, create a free account at the User Group Forums (http://forums.turbocad.com/) for lots of free help.
I transcribe older mechanical drawings into 3D objects that can be quoted online.
I design new devices and produce conceptual drawings or photorealistic renderings in either of the two rendering engines, Redway (a V-Ray variant) or LightWorks (currently an optional add-on).