Hello Teresa,
It is pretty normal to feel a bit overwhelmed with all the materials (and their prices). But even thou Matt is using “the best of the best”, it does not mean you can’t do the drawings with something more affordable.
When I started to draw, I remember I followed one pastel drawing of a bird on Gettin’ sketchy (Matt’s and Ashley’s youtube channel). It was one of my first drawings, and my materials were the cheapest you could find. I had one “drawing notebook” that cost me 1 euro and some pastels for kids.
I finished the drawing and I was quite happy (mostly because it was colorful 
), but of course, it looked different than Matt’s drawing. My paper didn’t allow me to use as many layers as his, and my pastels looked and behaved a bit differently as well, but well, I did what I could at that time.
Later on, after a few months, I learnt that there is a difference between oil pastels and soft pastels, and I realized that Matt was using soft pastels while I used oil pastels. No wonder it was quite different 
What I wanted to say is that, at the end of the day, the most important thing is to make a mark on paper.
Don’t get me wrong, I agree that quality materials will make a big difference, but if you can’t get it all, well, get it step by step and try to use what you can.
If I were you and I could choose what to invest in, between paper and material, I would probably invest in paper.
You are mentioning pastel classes, in that case, I would get one quality paper and use it in every pastel project (looks like you may have bought some already) and I would get some lower quality pastels. But that is only my personal opinion.
I would do the same for watercolor, I would get 100% cotton paper and some lower quality colors (winson&newton cotman is usually mentioned as a good alternative, I saw it here in Europe for about 20euros, when discounted it goes to 13euros). This would be if I wanted to follow some longer projects from the classes/lessons. If the paper would be still too expensive for me, I would just get some cheaper watercolor paper. And yes, it may behave a bit differently, but at least you will be painting.
If you are a complete beginner, maybe it is even better to get something cheaper first, so you don’t feel bad for messing it up :).
If you are open to different mediums, you could as well start with pencils, charcoal or with pen and ink.
I found these are most cheapest materials. You could check more lessons, what would feel the most appealing to you and go for that.
For a pencil drawing you would usually need maybe 3-4 pencils (HB, 2B, 4B, 6B), you don’t need a whole set and then some eraser (a kneaded eraser), and some good paper. This won’t cost so much and you can make some realistic drawings as well.
Charcoal is usually cheap as well, and I think you can mostly use the same paper as for pencils.
And pen and ink, you can get pen and ink pens and you good to go with even cheap paper for a printer.
Gettin’ Sketchy is very good for shorter projects, as it takes about 1 hour and you will have some finished drawing that you created, and I think you can use really whatever material you have at home, because it is “a quick sketch”. What I mean by that is, that if you do let’s say pencil drawing in Getting sketchy, there is a limited time to finish the drawing, so you will apply a few layers and that’s it, usually whatever paper that has some tooth will do.
In some classes/lessons, where the drawing is realistic and you spend 10 hours instead of 1 hour, you need a bit better paper, because you would want to apply lots of layers during that time. That’s why I think the paper makes a bigger difference than a brand of pencils in this case.
This is a very general opinion, because there are just too many things to speak about when speaking about different mediums, and while in one medium it does not have to matter as much (pencils, pen and ink..), the other can make a huge difference (for example color pencils, that is another world, where brand really matters).
Now, this is a long post, I hope you didn’t get lost and you are still here 
I am a beginner, so maybe somebody who has more experience can help you more.
You can as well tell us if there is a specific medium you want to do and if you are in Europe or US, people can maybe give you some brands that are cheaper but still good to use for the specific projects at the beginning.
Anyway, I hope you got something from this message and you will start creating some art, mostly with joy and without pressure. After you will learn what you really like, you can start slowly investing in materials.
Sometimes we can be stuck with all the things we need before we start that we forget to actually start.
Good luck with your journey and ask more questions if you have some 
Lucy
