Breaking an Promise

Is there ever a time when one should break a promise? I believe that we have to answer "yes" because there are times we make promises that can have eternal consequences. If I attempt to break an oath or a promise for personal gain the answer would be "no" but if in keeping my promise or oath I would damn myself or another to hell then we must break that promise. It is sad though that many Christians think that it is okay to break a promise if we were deceived and in keeping that promise would cause us financial or other personal lose. Isn't it better to suffer the lose than to break one's vow?