ZTE was selling their ZTE Open C which came with FirefoxOS 1.3 on ebay.co.uk, that's where I bought it from. I lived in the UK at the moment but I believe they were shipping it worldwide.
Checked the ebay listings again, there are a few sellers from Australia, the USA but seems like the ZTE listing is gone.
Checked the ebay listings again, there are a few sellers from Australia, the USA but seems like the ZTE listing is gone.