When someone complains about price gouging or being taken advantage of, they are stepping away from the most basic tenet of capitalism. That is a slippery slope that has cost our nation much and whose ultimate conclusion results in Socialism or communism. If you don't like the price, move along. The rule of supply and demand will always take care of itself. There certainly will be some short-term hiccups, but in the long the market will win out and the item will be priced appropriately.
On the flip side, don't complain about people's not buying an item at the price you've set. The old adage in real estate that it is location, location, location is wrong. It's price, price, price- there's always a buyer for an item when the price matches the perceived value to the buyer.
I would like to see a single, controlling list of criteria to sell on this forum. Simple, concise, bullet points that list he do's and don'ts.