Well, OpenPandora GmbH. is running out of OMAP3530s, so will soonish need to switch to the DM3730. However, that part does need to be tested, and that'd better happen before there are no OMAP3530s left... So that's the primary goal of this 150-unit run. But hey, might just as well sell them. It's only 150 units, pretty much a limited edition, so there's bound to be enough guys crazy enough to buy them at insane prices. As such, as there are buyers for that price, it IS a reasonable price. Simple rule of supply and demand.
Besides, the preorders were sold below-cost, causing OpenPandora to have a significant debt now, so simply needs to do anything that's profitable and reasonable.
If you want a 1GHz-Pandora for a more affordable price, you'll just have to wait until there are no more OMAP3530s left, which will happen, unless OP goes belly-up in the meantime, which will happen if everyone starts waiting for the 1GHz-Pandora...
IF I were OP, I'd start regular DM3730-production before running out of OMAP3530s, and continue to upsell them, until there are no more OMAP3530s, after which the price comes back down to OMAP3530-levels.
The price of the components (excluding LCD) is only a small portion of the total costs (I think <$80). PCB-production-costs are far more. As such, continuing the use of old parts will barely bring down costs, but all old parts do need to be sold off one way or the other...