When the first leak occurred a few days ago, the price of a cube was listed at 1.99 btc. That is was around $450, a great price for 30Gh/s.

Today 1.99 btc is $622. You are getting close to what you need to pay for a 30 Gh/s BFL box on ebay. By this weekend, if btc keeps rising, it may be hopelessly overpriced.