Thought the A332 had a brand new interior and they are only stop gap anyway until all the new metal comes our way.
The way fares are worked is the same all way through retail industry be it rail, shops or on line, lowest prices to get people booking and
as things start to sell well up go the prices and the closer the closing date the higher they go.
The holiday market is a prime target even on Heathrow flights so you cannot ignore it.