Send an e-mail to Jeff Bezos and ask if he'll honor that price :-)
It doesn't hurt to try. I've had great luck in the past when I e-mailed him. Just tell him that you're ready to buy it right now for $139.
I like my Kindle DX, but it the resolution is low and it makes it difficult to read magazine PDFs that I load on to it. It's great for reading regular books though.
The DX is not very good for reading pdfs. It does not render them very well and the pdf viewer is lacking in features. This is remedied a bit with jailbreaking and using other software. Personally, I am still disappointed at the lack of official updates for it, especially considering how much I paid for it (shortly after it came out).
If Amazon lowered it to that over the next few days, I would actually consider purchasing the (3+ year-old) DX.
The actual product page still says $239.
Do any HNers have recommendations for large eInk readers suitable for viewing pdfs/textbooks? I mostly read textbooks these days.