Typical DealExtreme. They pull this type of shit all the time. Item out of stock, they force you to cancel your original order, and then they re-stock same item with higher price and new SKU.
To be fair, I ordered one, and somehow my order was 24 hour before the whole entire world found out about it, and it was up on slickdeals, I just so happened to be browsing dx.com and was like wholy moly. So I was really rooting for myself to get one, but I knew realistically my odds were horseshit. So Everyeone started talking about the rumors, and lots of people starting cancelling there orders, and I just played it cool and took my time, and low and behold, about a few days to a week before the rest of the slickdeals people, the damn tablet shows up at my doorstep . I have alot of high end phones and tablets, but this thing is still to this day my favorite. I have a new KK 4.4.2 rom on it and customized like crazy.
Anyways... moral of the story is.... these companies aren't out to screw you... THey lost money on selling me that item. Others received the same deall.
However I think that they are not willing to do the same thing again, because it was there pricing fault the first time, so they have the morally honor it.... This time they are thinking if they dont do anything morally wrong, or post an incorrect price they will be safe.
So they simply change the s7800b models to s7800c models, and charge full price! Would have been easier to just change the price on the s7800b page back up to full price, and then restock the s7800b's.