I don't think it'll be cheaper than the 40gb, I mean, that'd be Sony middle-fingering everyone that bought the 40gb.
Also, I'm pretty sure sony wants to make a profit, so even if costs of making the 80gb is the same as the 40gb (assumption), them charging for the extra space would not be out of the ordinary, as the public probably understands that it would cost more to have more space.
I mean, look at the 360 Pro and Elite. I'm pretty sure the only 2 differences are colour and one has a bigger HDD, yet MS charge more for it.
I doubt it'll be $999 though, I'm going to say $799







