How quickly did the VMS leave the possession of those who understood it?

[oaken]

You could easily get away with a fraction of the work.

I have sometimes thought of this as well. The major basis of someone trying to sell the VMS circa 1430 would have been the unusual script since (as VMS researchers have discovered over the years) many parts of the VMS weren't that strange for someone familiar with manuscripts in the 15th century. During that time (since they didn't have the internet), one wouldn't be able to tell that it was not a pre-existing script. They would just be able to tell that it was not a common European script that they had seen. 

My point is that if they wanted to sell it, it would be much easier to make it crazier and make it largely readable for the potential buyer so that they could comprehend the uniqueness of it.

I am not convinced a hypothetical european VMS author would have the ability to create a version of the VMS even more out there than the existing one, let alone make it readable in addition. This was a period when a catholic european, even an educated one, would have had very little access to information about other cultures, philosophies or ideas. Trade with the Islamic world was only just beginning to flow again and Jewish communities, where present were insular, the reformation is still a hundred years away. With no other cultures to appropriate from, the author would have to create a manuscript with a legitimately interesting content, and the whole point of this theory is that writing a legitimately interesting and desirable manuscript is harder than making a superficially intriguing book of nonsense, interesting primarily in its illegibility.