This is my current work in progress

Hi! To me, your art look like Tier 4 or low Tier 3. As for prices, I think auctioning a couple pieces is a goody way to see what demand is and what people are willing to pay for your art. Also, because you're a very new artist (impressive work, by the way!), try to give yourself some time to practice and become more comfortable with your style before opening a shop. I love your more painted style! When smudging/painting your horse, try not to lose so much definition, as it makes the horse look a little flat. You could try using a smaller brush or adding more shadows and highlights to define the muscles and anatomy. The lovely Zomb's Start to Finish Art Tutorial is a great way to learn the basics about body prep. I hope that helps at least somewhat! <333