Sketches are $5 and colored pieces depend on what medium and how difficult it is.
I do pencile, marker, or digital, and honestly, digital will probably cost the most because while I'm not bad at it, it's annoying for me XD Pencile will be cheapest.
If you want shading on your sketch or if you want it inked, that'll be an extra $2-$3 depending on difficulty.
You can request something, but that doesn't mean I'll do it. I also play some internet sim games that I take currency in as well because I'm silly like that lol. So like if you play Khimeros or Gryffs, I'd take Tokens or Beads instead of USD.