I just noticed Expedia (and orbitz) added an option to pay for price protection if a flight goes down in price anytime between booking and the travel date. They refund the biggest difference you find within that time. You get the refund after you complete travel. The price for the protection is around 1.5% of the ticket. This may be worthwhile in some cases. I booked 7 tickets for the summer that dropped 140$ each when air France had 500$ tickets from TLV-NYC 2 weeks ago.