Let's see... $20/month (iPhone) + $50/month (base rate) + $20/month (unlimited data) = $90/month for one line.
I pay $100 for Verizon and 2GB of Data. I would rather pay $10 more a month for a far more grown out LTE network that Verizon offers.
You are comparing cost of Unlimited Data to Limited Data on Verizon at a higher cost and you still want Verizon...