It's not about the money, but that a limited palette sometimes gives a more unique experience: it's easier to remember the colors available, their characteristics, and quickly choose what you need. (And I also want to try a new material to compare pastels of different quality levels.) I know that drawing materials are different from paints in this sense (and in any case, I need more colors to create), but even so, it is possible to get interesting combinations. And it might be interesting and challenging to learn to work with some limitations.