Another cheaper vector drawing program worth looking at is Serif Drawplus (circa $100 US for the latest version, less down to free if you buy earlier versions)- if you look at RobA's sticky on different software that's available you can find more information there. Still...inkscape is free and pretty good too from what I've heard.

The best thing about Drawplus is that the learning curve is really quick which makes it a joy to use. Everything is intuitive.