Just wanted to put this out there. Purplus software has older versions of TurboCAD on sale - some for under $20: LINK

I've dealt with Purplus for a number of years and have always been pleased with their service. I've also used TurboCAD on my Mac for a number of years and am currently using the V5 (latest) version of it. But the older versions would be more than enough for most woodworking tasks. For the PC, the latest version is V16.

Even with the free version of Google SketchUp, there are some things that are easier drawn with CAD and then imported into SketchUp. So a $10 version of TurboCAD and free SketchUp and you're pretty well set up.