Sorry for the confusion. Modules bought from our online store can be used to build bluz into your own custom PCB, and these include the cost of provisioning them for the Particle cloud. You will use the CLI to do this, so there is no extra cost.
For people who buy their modules elsewhere or use the nrf51822 directly but want to provision it for the Particle cloud, they can purchase credits from us to provision it to the cloud. If you are interested in these prices, feel free to email us at email@example.com for pricing.
Let me know if that clears it up, and I will update the docs to make this clearer.