The eBook price wars have commenced. A few hours after Barnes & Noble slashed Nook prices, Amazon has announced a special $189 price for the Amazon Kindle–coupled with free shipping.

Here’s more from eBookNewser: “Amazon has dropped the price on the Kindle from $259 to $189. Borders is no longer going to be undercutting competitors with its $149 Kobo, which shipped this week. It will be interesting to see if prices drop again when Borders begins shipping Aluratek’s ‘Libre’ eBook Reader Pro, which went on presale for $119 earlier this month.”

What do you think–how low can we go? Earlier today Barnes & Noble unveiled the Nook Wi-Fi, an eReader selling for $149. Have we hit the sweet spot for an eReader? Or, like one author suggested, do we need a $49 Kindle?