I'm fairly new to 3D myself but just to offer an opinion ...
It can be expensive if you're chasing down the top of the line commercial software, but as you probably know there are open source alternatives to some things, such as Blender. It's nice to have Max sure, but you don't need it to get started.
I think it also depends on what you're looking to do. If this is a hobby, then it can be an expensive hobby.
If on the other hand, you view yourself as an entrepreneur, it's really cheap relatively speaking. I've started a landscape company, a photography business and a recording studio (obviously I'm a bit older), and all of those cost tens of thousands of dollars to really get to any sort of commercial level. It took starting small and working my way up and finding ways to produce with what I could afford along the way.
If you're a student, there are discounts for many applications.
If you're looking to become an employee in the field, like anything else you're going to incur bills whether that be in education or the cost of living, etc.
I've yet to find anything that you can get money out of, without putting some investment into it first. But $20/month is about as cheap as it gets for commercial software, especially when you're getting an entire suite as with Substance. That's a lot of bang for the buck. And you mentioned the downloadable materials ... to me those are all gravy, you're also getting the tools to make your own materials.
You don't need to try to buy everything all at once to produce results. It would help if you mentioned what your goal is.