The problem is that HP (nor any technology company, really) is prepared to sell their items for a loss to gain market share and hope apps/accessories sales bring the whole production line into the black. It will be interesting to see how much Amazon prices their new tablet at--although I instantly wrote it off since it's only a 7" screen.
IIRC, you could get the pre-fire sale 16gb for $400, which is only $100 above HP's manufacturing costs (and does not include marketing and R&D). There is very little margin below that $400 price point.