The reason I know this to be true is that I have suffered this first hand. I spent wads of money on fancy pencils and paints to no avail. In reality buying the expensive materials made me worse as I treated them as "precious". Currently I would consider myself at an intermediate stage, I am no novice but I have a long way to go and I currenty use both expensive materials and cheap ones depending on what I'm working on. For example I use Old Holland oil paint (most expensive paint you can get) and winsor and newton "winton" oil paints (very cheap paint) Are my paintings with the Old Holland paints better than with the cheap paint? no!!!! as expensive as they are they are not made of magic and are basicly the same as the cheap paint.
Image taken from internetSo whats my point? resisist the temptation to ask other artists what materials tey used, it will not help you in any way, instead try to see how you can use the materials you have to recreate the effect that you see in their work. If you are unable to do thisit is more than likely a promlem with your technique rather than the materials and it would be a much better investment to spend your hard earned cash on books or videos about painting than chasing specific materials that cannot help you.