For me the issue with the iPad is not its cost, not at all. I love that it does most of what I need to do on the road and it is so freaking light, small and the battery life is 10 hours. It is versatile.
It is an iPad 1 that we bought before our trip to Mexico last November. The laptop stays in the office on most of my business trips now. I would never pull my laptop out on my commute to the office (about 30 minutes), I always pull out my iPad, surf the web or read books or look at photos of our trips to Mexico
That said, if it will not do what you want it to, there is not much point of getting one. It sounds like an iPad will do what you want it to.
There are also Android tablets, but I would be careful with them. An article yesterday revealed that most mobile device malware attacks are aimed at the Android OS, and there have been cases of apps showing up in the Android Marketplace with malware embedded in them.
Good luck with your purchase decision!!