I'm going to have to disagree with you on this. $1000.00 for a $70.00 penny is an egregious example with a HUGE difference in asking-price and actual value. I would imagine most of these are more of a doubling or tripling in value for a coin and are harder to determine, especially when price guides vary as much as they do.
Price gouging varies in it's forms. I don't begrudge anyone from trying to make a profit on their coins. In fact if the guy gets a grand for his Penny, good on him. I still find him to be an unscrupulous person and a poor reflection on the community. If he is in fact tied into NGC or PCGS his character would reflect the character of those companies by virtue of association.