This is one of those instances where it helps to go to the
source article:
"The Plastic Logic will be launched in the US at the beginning of next year at a similar price to the Kindle, which starts at $299."
Since we know the Plastic Logic reader is comparable to the DX, it makes sense that the price would be similar to the DX model, not the Kindle 2 (which is the model that "starts at $299"). So basically they're saying the price is expected to be in the ~$500ish range. As someone else already pointed out, the "expected to be" prices tend to be on the low side, so I won't be surprised if it's closer to $550 or $600 when it actually is released. That is unless they offer some sort of partnership discount with it (a la "buy a year of the NYTimes and get it for $450"). Of course, this is all just speculation on my part. But I like to speculate.