What you're missing, is that Steam's heavily discounted sales exist because the games cannot be resold. Just compare Steam to the market for new/used console games.
That is to say, the situation you're describing should never exist -- games will be either cheap (current situation) or more expensive with a secondary used market.
That is to say, the situation you're describing should never exist -- games will be either cheap (current situation) or more expensive with a secondary used market.