Same here, I don't want to pay Verizon or AT&T more than I already do.
So, iPad with Wi-Fi only is fine if you are usually at places with Wi-Fi networks available, or you have an iPhone with you to back you up for places when you don't have Wi-Fi.
For me, it's either at home, work, train or class. Home, work and college, I have Wi-Fi available. And train, I'm underground for 95% of my journey. So, if I need anything that requires data, I just use my phone.
If you are really concerned with needing some sort of connection on your iPad, (If no one's said this already..) one thing you can do is jail break your phone and make it a hotspot and connect to it from your iPad. =)
Edit: JMG already said about jail breaking. My bad! xD