did the vga front camera make sense in a way?

Now that I think about it, facetime over cellular with the newer camera would use up data alot more quickly wouldn't it? With my 2gb plan on verizon, I'm wondering how long I could have a FaceTime call without going over. Could anyone with an unlimited plan test this out?

Maybe if there was an toggle option to switch to lower quality video it would be great for saving data.