Id question what you want to do and why you think you need so many brushes. What do you actually want to paint/create?
I’ve only texture painted one thing so far but I only needed one main brush, which I made myself, along with a few stencil textures which I also made myself from images I found online.
I would save your money and have a go first to see how you get on. Don’t forget you can layer up your textures and combine them with other materials.
What’s a must is a tablet. If you don’t have one of those then buy that before any brushes.