Real bargains can often be found at such times. The graph below shows one reason for the variation in prices from Honolulu to Manila. Now, China Airlines is prohibited from flying the last leg, Taipei to Manila by the Philippine government and Philippine Airlines reduced service to 2 flights per week. The result is approximately 4800 less available seats PER WEEK at the Summer Peak season. While the ban on China Airlines has been lifted, Philippine Airlines still has only two flights per week boarding or debarking in Honolulu and Eva Air no longer flies to Honolulu at all although they now can go to Manila again.
Airlines change their fares frequently.
If a particular flight on a given day has empty seats, the airline may offer greatly reduced fares to fill those seats. While usually a discount wholesale provider has prices considerably below the price offered to the public by the airline directly, their prices are based on a contracted monthly or other fixed period of time rate. Because of this, wholesalers seldom have unsold seats, but it does happen. In either case, unsold seats may be available at greatly reduced prices, but only for that one flight. Also, just as I have seen seats disappear while searching the CRS, I have also seen them suddenly appear when someone cancels.