I was just booking a one-way trip from Barcelona to Marseille for next summer hoping to use some points sitting on a bank-based (but not airline-affiliated) card. Imagine my shock when the ticket (which I knew should cost about $89) showed up as 70,000 points. At the bank's value, that would be about a $700 ticket.
So I did a bit of looking and discovered that the bank uses Travelocity...and Travelocity's website shows only tickets at $1045 on Iberia, flying backwards from Barcelona to Madrid, changing planes and then flying to Marseille!
I went back to Momondo.com, and sure enough...the $89 fare was still there, non-stop on Vueling (which is a subsidiary of the company that owns British Air and Iberia). It's a 10:30 am flight; waiting for the 5:50 pm flight would knock the price down to $62. I called Travelocity directly...they told me that only Iberia served that route, and that there were no coach seats available...for next July, 9 months away! Well, so much for getting the seats with those points...I booked them for (gulp!) actual money.
Curiosity sent me around to more search engines.
Kayak.com, usually one of my favorites, had the Vueling seats--but quoted a price of $172. When I clicked through to Vueling, the price was $89 (actually 59.99&euro.
Expedia shows seats from around $260 on up to over $600...but not on Vueling or any of the other budget carriers. These seats are one-hoppers via Rome, Paris, Amsterdam, several cities in Germany, etc., and the connections make the 65-minute flight into an odyssey of up to 15 hours.
Skyscanner.net and whichbudget.com both show the two Vueling non-stops...but skyscanner also lists the various two-hop solutions, including a bizarre itinerary that would have us take a 45-minute flight from Barcelona to Palma to Barcelona (with a 9-hour layover) arriving back in Barcelona in time for the morning non-stop to Marseille!
So, folks--look around a whole lot before you settle on a fare that looks high, and don't assume your favorite (or biggest) engine will always produce the best results!