The Mandate of Heaven is now available for $2.99 (or local currency equivalent) on all the major eBook stores. I have included some direct links below for your convenience –
The Mandate of Heaven – Amazon (US)
The Mandate of Heaven – Amazon (UK)
The Mandate of Heaven – Apple (US)
The Mandate of Heaven – Apple (UK)
If you have a Sony eReader or any other device you can find suitable downloads from smashwords.com