Right, you're not paying for C# you're paying for an IDE. You don't need VS to use C#. Especially now with Roslyn a the c# language server a lot of other IDEs can do a lot of the same things VS can do.
And if you're working on open source/non-commercially, the free community edition is also a good option.
Indie devs and small businesses (<5 installs) can use the community edition for commercial purposes, too. I use VS Code & the C# extension most of the time, and that's free as in beer for use by anybody.