A name to attach to the origins of the manuscript

[Rafal]

Thank you for that answer.

I will always quote it when someone says Voynich Manuscript is written on vellum   I believe low quality of VM is an objective thing and I trust you in that matter.

And you raise an important point. We don't know the place where Voynich Manuscript was created so discussing prices and literacy may be hard.
It was certainly different for example in Italy and Russia.

And it could be different through time. If we ask "How much cost a car in the 20th century?", we immediately see the oversimplification. In the 1910s  a car was a luxurious thing but in the 1990s it was no more. In the 1960s in USA everyone owned a car but in Soviet Union 5-10% of people owned a car.

Speaking of Voynich Manuscript we can make an assumption like  "it was made in southern Germany in the 1420s" and work with that assumption. I think it is acceptable approach but you must be conscious that all your logic is no more sure as your initial assumption.