Use anything and anything, that’s the way.
High-end products won’t make any more of your talent than cheap materials. I’m far more interested in what an artist has to communicate than the materials they used; unless the specific materials are related to the art in question, obviously.
I work with all sorts of materials, physical and digital, but I’d echo @quorihunter above in that paper is more important than pencils. I also do makeup design, and for that medium the quality of the brushes is far more important than the makeup products used. You can borrow my pencil, but nobody touches my brushes 
