Vuforia asking big amount money :(

Here is south korea.
We made education app based on vuforia AR.
This app is for public school serviced by government for public educate by freely.
Last week PTC(Vuforia compony)'s attorney send document.
They asking $34,397 per year/app. ((
It total 50 apps. per year $1,719,850 ?????????????????
It's for free public education service by government.
Unity tech you know?
Your base include lib "Vuforia".
How can doing like this?
What's going on?????????