Other shoppers ready to buy
While waiting for the price to drop as low as possible, be warned, there will be other shoppers watching too. Wait too long and they will purchase before you.
Price drops are often set to occur over a 1-3 month period. If you miss the low price and it jumps back to its standard price then you may have to wait that period again, or worse, the discounting may be set to not repeat and you will loose your opportunity completely.