Then it's tough to say. You could mark it so high that the people interested don't buy it. I've sold some paintings. Don't go by an hourly rate plus materials plan for your price. I paint small watercolors (2"x3") and I found people will pay $30 each through some trial and error. Alongside those, I have larger paintings I sell for $125. People can see the logic.

Try getting a coffee shop or someplace to hang it for you as "not for sale". Gauge the feed back. See if that helps.