I used TripAdvisor's flight finder (along with Kayak) to find a flight to Cozumel, and the best price that the searches found for a flight that I wanted was from CheapOAir. I clicked on the link to go to CheapOAir, filled in everything, and hit Book Now. It came back with a screen saying that the two tickets were no longer available at that price but that they were available for well over $1,000 more. I declined, returned to CheapOAir's search page, and the same flight was still listed as available at the original price. Tried again, same result. I then noticed that the exact same combination of flights for a few dollars more. I tried this one, hit Book Now, and a screen came back saying that price was no longer available, but I could get the tickets for $500 more. I declined and took one last look. Once again, the exact same combination of flights was listed as available for yet a few dollars more. I tried one last time, and this time it went through, allowing me to buy the two tickets for about $60 more than originally listed.
I eventually got the combination of flights that I wanted at a reasonable price, but I was very disappointed that they tried to gouge me for over $1,000 and then for over $500 for tickets that were obviously available for, at most, $60 more than their originally advertised price. It will have to be an EXTRAORDINARY deal for me to do business with them again.