I can understand completely! No worries. I am sure there is a way to sell through DeviantArt...I can do a bit of research and see what I can find out about the process and get back to you. Then you have that option if you want it. Being that you used Photoshop, it is probably already high resolution, which is important if you want to sell prints. Personally, I would love to have your painting of Snape as a mural on my bedroom wall, but I think my husband might be a little weirded out by that! (grin)
Let me see what I can learn, and get back to you. You are a fabulous artist! I wish that I had that kind of talent...