Well, if you're selling FSBO, you can do whatever you darned well please. You're not subject to any code of ethics, what's the problem? (Jersey folk, do not hesitate to correct me!)
But. Nobody in their right mind will meet your price and then agree to your raising the price. "Whoa! I'm giving you what you asked for, and now you're RAISING the price?"
I'm not even going to ask how we go from "No units had sold in over a year" to "my next door neighbor sold."