My history is that I had a 1GB plan and it was running out about 5 days before due date so dial up speed. For $5 a month, I was able to double my data to 2 GB and never ran out. HOWEVER - with recent talks with Vodafone, I discovered that I could get 5GB for $4 more per month so signed up for that given that my life has changed and I will be downloading heaps of photo sites while I look for a new place to move too.
I have no idea what others are talking about with 10GB+ allowance because I would NEVER use that but that is what you have to look at. I rarely go onto UTube and have never downloaded Music, Films etc so it really comes down to what you want Internet to do for you.
I am happy to watch TV on the TV and I think we have to be rational about what we do and what we want. Why would I need a mobile phone as a normal person (not business related) to download emails. Not interested - I will talk to you when I get home! So hope that puts it into perspective. I have no children living with me gaming etc so my needs are fairly basic and I am happy with that.