50g is definitely a respectable starting price, though c: As you get more practice, you can start to charge more. :heart:
Also, do you have any animation experience? Working with paint art makes it very easy to do animations, which almost always boosts the perceived 'value' of your art. You don't have to download anything, either.
Here's the site I use to make animations like
this,
this and
this. c: I hope that helps.
One other thing to remember is that a catchy title, some color and maybe a banner helps spice up your shop and draws more customers in. Here on Mene, they tend to frown on extremely graphic-heavy posts, however, so keep it to one eye-catching banner and some thumbnails of your work c: As you're working with pixels, you could definitely get away with posting the full image instead of linking out.