I was considering this years ago and decided it was not doable because of lack of internet. If you actually look at Hughsnet you'll see how fucking terrible their shit is. You have terrible restrictions on max upload/download per day (like 500 MB download). Also the speeds are pure shit too.. all for a huge price. Even their best packages are pure shit.
If you rely on Wifi you're not really going to be going anywhere special.
I don't know too much about Sprint 3G, but can't imagine it's much better than Hughesnet.
I'm guessing you're the type that needs some good reliable internet is why I'm saying this.
Oh also, you can't just park your camper anywhere. You'll have to pay campgrounds or whatever and they are often much more money than you'd think. Comparing it to apartment rent - it might be the same.. it depends on if you can find good deals.
if you get something that works though keep us posted.