I have a plastic Gann wheel (based on the square of nine) for sale - $65.00 plus shipping. It's not the holy grail and if you don't know what a Gann wheel is then it's probably not for you. If you're studying Gann theory then it's nice to have.
You can get it FREE here http://www.beginnertrader.com/ has hundreds of PDFs FREE about Gann etc and all things planetary and galactic