The price continues to tumble, it's not that long ago this was about £470.
Adult price is not quite as good a price as the Opodo/Turkish Airline deal from Heathrow, but if Gatwick is your chosen airport and you are travelling with Children then this deal may be better for you. Could argue that Emirates is a more prestigous airline as well.
Seems to be for dates in June only (several days available), changing in Dubai with good departure times and short stopovers.
June can be considered the 'low season' in Thailand, but what that often means is it's sunny all day and rains for about half an hour in the evening and cools everything down, a welcome treat!