I do freelance illustration as a hobby. Because it’s a side thing, my prices aren’t high: just $20 for a lineart sketch and $35 for colored.
Client: I’d like the cheapest commission option.
Me: Okay, what do you want?
Client: I want a design of my character, but can you color the sketch?
Me: I’d have to charge more for that.
Client: but you just have to put color on it! It won’t be hard.
Me: Yes it will.
Client: I could do that in five minutes, so why can’t you just charge the uncolored price for it?