For most CS students in the world, 'don't mind' is not an option, they simply don't have that money.
I have paid for Windows licenses, for MSDN subscriptions, for Visual Studio, for Oracle databases, for ERP tools, for Solaris, for Red Hat and countless others but, quite frankly, I haven't felt a compulsion to pay for tools for a long time now (PyCharm is sweet though).
We have from excellent compilers, IDEs, databases, operating systems all the way to datacenter automation solutions that are free. And, in the case of students, they are also open-source so they can be studied (which used to be an important part of life for students) and extended (which is a nice advantage not necessarily but usually associated to tools you don't have to pay for.
So, what prohibitively expensive real world tools are you thinking of?