So the question is, if you had 100 5 gh/s units ready to sell for $247.00 each right now, and selling them would get you a huge chunk of the market share coming up, why would you be mining with them to generate ~$2,700 a day in Bitcoin?
500 GH/s will get your roughly 0.6% of the bitcoin network. The Bitcoin network is dominated by Avalon and ASICMiner. Their devices together could easily account for over 50% of the hash rate now that Avalon is shipping batch 2.
Also, BFL had to include twice as many chips as planned in order to get their advertised hash rate. If they are doing small batches of chips (100 or so) on an MPW prototype run, their chips are quite expensive ($50-100) and that would eat their margins (thus explaining their price hike on Jalapenos). If they are only making $50 per device, then $2700 a day looks good. Especially if they are in a cash crunch.
Personally, I don't think BFL has enough units working to make that much.