[Wintermute]

You can pick up orphan pots like this with a decisive raise at virtually any point post-flop. Particularly if you have a tight image, which I suspect you do.

A good rule of thumb--min-bets never like to call a max raise. Unless your opponent knows that you know this, and is baiting you, which virtually never happens at this level, and rarely happens at levels up to $600 or so.