I don't think anyone will prefer to buy if price falls back to $1 and if it goes that low then it will be surely an end of bitcoin and there would be no point in buying them at that stage.
Going back to $1 means the bad news is really heavy. No way bitcoin price will fall to $1 if there is no major bad news that will happen.
Also why it doesn't have established a support when the price reached $400 , $300 or $100 and really goes down to $1? That is the end of bitcoin if that will happened. No way it will gain trust again after the established progress today of bitcoin.