questions about the coming Power BI Embedded SDK

[venape]

have read one passage "Power BI Embedded SDK for Node JS" from Josh Caplan  on Microsoft Power BI Blog 

quote as

"All calls through the SDK are authorized by an app token. The SDK includes built in support to generate app tokens based on API usage. The app tokens are signed using the access key that is generated when you create your workspace collection in Azure"

so  questions are:

1), does it imply that one user of Azure can get only one app token to accesss Power BI Embedded REST APIs?

2), how much it will cost for Azure as using the generated access key