I just bought one. We'll see how this goes. I at least got to use my $420 coupon, so it was only a bit over $2k all said and done. This all depends on how many they are going to sell. Considering they limited it to 1 per person, hopefully not a ton. If the 2,500 rumor is true, then that means around $100 per day with the current price. If that was bullshit and they sell 10 times that, then it's like $10 a day. Knowing my luck they'll sell a ton of them and the price of the coin will crash though. One positive though is that the coin isn't going to fork, which is going to be a risk with a lot of new models that get released in the coming months.
Edit: They just sold out, so at least that is promising.
I think you bring up the most important point. How many will Bitmain sell in batch 2, 3 & 4. With the A3 (batch 1 was $2375, batch 2&3 = $930, batch 4 = $520) They dropped the batch 2 price by more than half for a 40 day later delivery.
Think I am gonna wait for a batch 2 or 3 on this one. It is tempting, but I know that they will follow with more b3 miners. Many more and probably at half the price.
Probably there shall be gaps for several weeks prior to next batch to be announced (and cheaper). I doubt they will stick with current sales figures, there must be more to offer from Bitmain. Waiting anxiously.