You don't have to have a whole bunch of Copic's to do a cute coloring job. Look how adorable this image by Mo Manning looks with just 6 colors and the blender if you need to fix a mistake. The image is called Tolerance there is also a girl called Patience. I couldn't find it on Mo's store to link it, but I'm sure if you asked her she could find it.
But what if you added 6 more colors making it 12 colors? Look how much character those 6 extra colors add. These 6 or 12 colors would be a great staring point if your looking to start your Copic collection. They are colors I use all the time!