There are a couple others:
Check AutoDesk - they build AutoCad, AutoCad Lite and QuickCad/QuickSketch (and many others). I use QuickCad at home and it's an entry level product. You can add plug ins that allow you to import/export files in standard autocad formats used in CAM. Once you have a need to go up to AutoCad - you have already used the drawing interface. I think I got QuickCad for $180.
http://usa.autodesk.com/adsk/servlet...&siteID=123112
At work we use a Mac platform. We use VectorWorks 2008 here in engineering. It's much easier then command line drawing like what is in AutoCad. I started CAD work on a MAC using MiniCad (product is now Vectorworks) and it was very easy to learn/operate. You can start with VectorWorks Fundamentals as an entry level product - and then upgrade as needed.
http://www.nemetschek.net/
I recently ordered SolidWorks for $200 for home use.
http://www.solidworks.com/
Here's a free download demo if you want to try it out first.
http://mkt.solidworks.com/emarketing...external+short
Jim