Always check it in the official page:

http://www.amazon.com/gp/product/B0015TCML0?ie=UTF8&tag=ereader-2-20&linkCode=as2&camp=1789&creative=390957&creativeASIN=B0015TCML0 (Kindle DX)

http://www.amazon.com/gp/product/B00154JDAI?ie=UTF8&tag=ereader-2-20&linkCode=as2&camp=1789&creative=390957&creativeASIN=B00154JDAI (Kindle 2)

If they are doing promotion, they will show up on the official page. Beware of sites other than Amazon which claim to have cheaper price. They are either just linking to Amazon giving the same price, or they are fraud. I never hear any one can get a "new" Kindle with a price cheaper than that on Amazon.

Go here for the cheapest new Kindles:

kindlesalediscount.happy2beme.com/

or here

http://www.amazon.com/gp/product/B00154JDAI?tag=collplan101-20

You can buy a cheap one at: http://www.mobileereaders.com

Hope it helps!

Beware of sites other than Amazon which claim to have cheaper price.
Only Amazon sell the kindle product and price is fixed.
Many Amazon associate stores selling kindle but It is just door to Amazon store.
I bought mine at http://kindlexstore.com/ and I am happy with it.

The Kindle 2 just announced a price drop. It is now under $300, check it here:

http://www.amazon.com/gp/product/B00154JDAI?ie=UTF8&tag=searchresult-20&linkCode=as2&camp=1789&creative=390957&creativeASIN=B00154JDAI

Seems the Kindle DX still remains at the original price:

http://www.amazon.com/gp/product/B0015TCML0?ie=UTF8&tag=searchresult-20&linkCode=as2&camp=1789&creative=390957&creativeASIN=B0015TCML0

Be careful where you go… There are a lot of scam sites out there. Kindle is still in high demand, so there’s really no reason to sell one cheap unless it’s used. Here’s a link that might help you out

Amazon just announced a price slash on the Kindle 2. It is now $60 cheaper than the price when I bought mine… Remember, always to check it on the official site, and don’t go to place order on sites other than Amazon:

http://www.amazon.com/gp/product/B00154JDAI?ie=UTF8&tag=moreinfo-po-20&linkCode=as2&camp=1789&creative=390957&creativeASIN=B00154JDAI

you can get it on Amazon cheap:

http://www.amazon.com/gp/product/B00154JDAI?ie=UTF8&tag=health0d8-20&linkCode=as2&camp=1789&creative=390957&creativeASIN=B00154JDAI

See it here. The best price is now less than $300:

http://www.amazon.com/gp/product/B00154JDAI?ie=UTF8&tag=more_info-20&linkCode=as2&camp=1789&creative=9325&creativeASIN=B00154JDAI

I found here is the best price for the Kindle 2:

http://www.amazon.com/gp/product/B00154JDAI?ie=UTF8&tag=querystr-20&linkCode=as2&camp=1789&creative=390957&creativeASIN=B00154JDAI

And here is the best price for the Kindle DX:

http://www.amazon.com/gp/product/B0015TCML0?ie=UTF8&tag=querystr-20&linkCode=as2&camp=1789&creative=390957&creativeASIN=B0015TCML0

Hope this helps.