You might want to look in to Solid Edge. It is a 2D drafting program from Siemens that is upgradeable to a 3D environment. Pretty simple and fairly impressive. The 2D product is no charge, they want to get you hooked and then transition to 3D which is price competitive with a lot of other 3D environments out there.
The web site is
http://www.ugs.com/products/velocity...olidEdge.shtml
Ed