It's really hard to answer because It changes a lot every month and, to be completely honest, I prefer not give specific numbers(I'm sorry☹️).
If you want to start selling your pixelart I totally recommend it. It may not be a full time job salary, but with some time invested on it, and a bunch of releases, It can get to a point where It turns to be a nice side/complementary income. Then you can expand and create a patreon, Stream on Twitch while creating the stuff you're going to sell, etc. so you get the most out of it.