Feature Request: Pay-To-blog - Make use of levels

Pay-To-blog needs the ability to make use of the Pro site levels. So I can set a minimum level for which users are not required to Pay-To-blog.

This feature request is taking into consideration the freemium module. I would like to be able to provide free sites (Free Level) with limited features (diskspace, pages ext.) which would then encourage users to upgrade and While I'm still able to disable front end and backend for unpaid sites (None free Level)

Currently Once Pay-To-blog is activate the entire site is locked off to only paying customers making the freemium module impossible and if Pay-To-blog is not enabled I can't disable unpaid pro sites.