It is not well known that the Gra would not have held of the idea of paying people to learn Torah. You can see in his commentary  on Pirkei Avot on the Mishna in the first chapter that says not to use Torah to make money from he brings the event with the vessels of the Temple that were used by the king of Babylon. And also he brings the actual verse of Meila. [That is the prohibition of using something that was dedicated to the Temple for one's own use]. 

How does meila work? It is like this. Let's say you have a pen and you say, ''This pen is sanctified to the Temple.''  At that point, you can not use it,- nor anyone else. It must be brought to the Temple and sold and the proceeds go to different needs of the Temple.  This is how the Gra sees learning Torah. One must not get paid for doing so because that is the same as using a vessel that has been dedicated to the Temple.