So the iPad is finally here, and the first impressions are a bit mixed. Om thinks it’s the device we’ve been waiting for. But it didn’t quite make Walt Mossberg swoon, at least not yet. Dan Rayburn complains that he can’t prop it up to watch video, while Major League Baseball is all over it. My question concerns the total cost of owning and using an iPad. If you go for the 64GB version with 3G it will run you $829. Fair enough, but then you need a $30 per month ($360 per year) data plan, plus $9.99 a piece for apps, plus the cost of whatever content you buy. Pretty soon, it could start to look like your cable bill.