I have been exploring DraftSight, which is a free (as in beer) 2D CAD program that seems to be very cross-compatible with AutoCAD. It is available in Windows, Mac, and Linux versions, as well. It won't give you the 3 dimensional capabilities, but it's a full featured program (parent company also produces Solid Works and other CAD software).
http://www.3ds.com/products/draftsight/overview/ As for your criteria, you can't beat the cost, and I find the user interface easy to work with after having worked with AutoCAD for many years. And, since it's developed by a commercial software company, and they've produced it for three different operating systems, it seems pretty complete and well done. I think it's worth checking out.
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Philip Proefrock AIA
Ann Arbor MI
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Original Message:
From: Matthew Keller
I'd like to have a CAD program for my home computer. I'm dismayed by the cost of Autocad and Revit (wish I had stock in Autodesk). At work, I'm a Revit user, but I'm willing to try something else for personal projects at home.
Any comments/suggestions with regard to cost, user interface, and quality?