The Kindle is cheaper on the get go because you really can't get an iPad for less than $300 if you are lucky. Having said that, I own an iPad and I love it. Because we own multiple Apple products, I love that once you buy for one, you never buy again. I put my documents, mail , calendar, photos, movies and most of it syncs to my computer. You can buy a model with service and service is per month basis, no contract and for us it is about $30. We buy it only when we go out of road trip months. BUT, the wireless models are more expensive. It does pretty much everything besides intense applications like Excel graphing and hard core Photoshop (just basic stuff). It plays Netflix and if you do go WiFi, just remember that most places have hotspots.
For price:
The Kindle Fire HD 8.9" with WiFi (but not 4G) is $299.
3rd Gen iPad with WiFi (but not 4G) starts at $499 (2nd Gen iPad for $399).
The Kindle Fire HD 8.9" with WiFi and 4G is $499.
The third generation iPad with WiFi and 4G is starts at $629.
The Kindle is going to be cheaper by far to start and if you never buy anything else and don't plan on buying many apps, it's the economical way to go. If you are an Amazon user, by all means get the Kindle. If you want to read, both carry Kindle. You can use Amazon on the iPad, by the way. I just think iPad is more versatile but that's just me with out many iPhones, iPods and iPads.