ED has gotten several offers from investors to finance batch 2. It's all about being able to sell enough Pandoras to recoup that investment. If it's possible to sell 600MHz Pandoras for $500, and 1000Mhz/512MB Pandoras for $750, then do it.
I think those prices are way too expensive. It's cheaper than that to get devices that have better specs and are mobile phones, and you'll have a hard time convincing most people to choose a Pandora instead of a modern smartphone, including me (I would also have a hard time explaining such a choice to friends and family).
I think it could even make the 600MHz Pandoras look bad, because after seeing the overpriced $750 price tag, people may look at the 600MHz price and think that it's also based on a big profit margin rather than the mess of the last couple of years.