They only reduced the prices for compute engine, bigquery, appengine, and cloud storage which are developer oriented cloud services and therefore unrelated to box. If google beefed up google drive, then it could be an attempt to throw a wrench in the gears of box.
I personally think google has more incentive to do the latter. Millions of people and thousands of companies already use gmail. It'd be pretty easy to convince people to take those files they already send/receive using gmail and push them to google drive. Convincing hardcore AWS users to move to google app engine might be a bit tougher.