Depending on your circumstance, the cheapest way to get the data active on your VZW iPad is to add it to a share everything data plan. My wife and I have 4GB data between two iPhones, and I added my LTE iPad 4 for $10/month. Now mind you I don't use a ton of data, but for $10 a month it's a pretty good deal. I think the next step to 6GB data is only an additional 10 bucks a month as well.
Just a thought.