said by yyzlhr:
To be clear this is not a $30 add on for unlimited. These are completely different tiers that offer you unlimited usage. If you sign up you will have one line item on your bill. For example if you have Express it will say Express $81.99 not Express $51.99 and Unlimited Usage Add on $30. However, if you have discounts, it will discount based on the capped tier, so you will see Express $81.99 and then a $36.40 discount (70%) not a $57.40 discount.
A little disappointing, but thanks for clearing it up.