Licenses are documents to which copyright can apply, and the copyright terms of a license itself don't need to have anything to do with its content. So you can "license a license" and prohibit anyone from using your license unless they pay a fee. However, be aware that:

* Most people won't consider this in accordance to the FLOSS spirit, so you will have a hard time to convince the community that your license is worth it.
* There already is a large number of open source licenses which cover most common use-cases which are competing with yours and which can be applied for free. And when there isn't one which covers your novel idea, it won't take long until one shows up which expresses the same idea with different words and thus circumvents your copyright (because this is what the FLOSS community does). What could protect you from this is a patent, but I am not sure if contract clauses are patentable.
* Make sure your licensing model for the license does not prevent the license from being *libre*. For example, when your license mandates a strong copyleft and at the same time the "license license" mandates that every sub-licensee also buys a "license license" from you, then the work it is applied to is no longer free software.