Okay so I'm utterly clueless when it comes to how much my art would be worth. I really need to start a shop on etsy to help with medical care costs but I really have no idea what my stuff is worth. What would you suggest?

I can do pretty much anything as far as custom art on fabrics(shoes, bags, ties in the case of my reference. I used to do digital art and watercolor so I have a decently wide range of ability. This is a tie I made last Christmas. How much would you spend on it or something similar?

Additionally I have a pair of tan(canvas) colored Toms style shoes. If anyone has any bright ideas on what I should paint on them feel free to suggest. My muse has completely abandoned me here.