Given the current rate of difficulty increases, over 50$ per GH is absurdly overpriced for a 25 GH miner with an October delivery date. Folks would be much better off simply holding their BTC or spending $1300 to buy bitcoin directly.
Currently these miners are being deployed for 100TH mine project and are the most "trusted" pre-deliverable available.
The 400 GH October delivery has a decent chance to make ROI at $20/GH, but I still think the 25 GH October delivery is absurdly overpriced at over $50/GH.
By October, I suspect you'll be able to get a Blade for under $50/GH given the recent ASICMiner price drops.