While the Kindle Fire is less expensive that the iPad, the prices have dropped on the iPads. And I do like the better parental control options = and the rumor mill points to Apple readying a new feature that will allow more parental controls in the near future, many suspect because it's looking likely Apple will add a payment component to the device much like Google Wallet or Square's Card Case.
The iPad is a great overall device, but it is more delicate. If you do go that route, get a good case to protect it against breakage.