The prices for Bali are reviewed every 4 months or so but the next one i think will be a little later, in March 09 at the moment is the word at the moment.
If you book now though, you pay the price as it's stated on the web site - if you wait until March and the price goes up, you pay the new price.
I'm not saying it's impossible for prices to go down, but this very rarely happens.