As tablets go, the popular Kindle Fire is everything the iPad is not: small, built on Android, steeped in the Amazon ecosystem... and perhaps most of all, cheap. It's getting a little cheaper still today on news that recertified refurb units — complete with one-year warranties — are available as an Amazon Gold Box special today for $139, $30 off the normal refurb price of $169 (and $60 off the new retail price of $199). Amazon warns that the deal could end even sooner if it runs out — so if this deal piques your interest, you probably don't want to wait.