The second batch being more expensive has happened with other Bitmain miners in the past like the D3 IIRC, though I don't have the exact numbers for the pricing for the first and second batch of that particular miner.

I doubt sales were that great for the E3 in the first place, and they still chose to raise the pricing for the next batch. Interesting moves on the side of Bitmain. Anyone who buys an E3 at this price is throwing their money away, and even the $800 E3 was a gamble.