So if you haven't gotten it from one of the other e-tailers, you can now snag Ghost Dust for free here. So glad Amazon caught up to the rest of us!
Update: There seems to be an issue with the international Amazon stores' prices, and this price change. International readers, feel free to email me at nicwilson.writer at gmail.com (You know what to do with the at). I'll send you a free copy. Hopefully they'll be able to sort it out, but in the meantime, you can still get it free from other e-tailers, or contact me for a copy.