You will need to go on a Blackberry Plan for sure to get email and browse with the Blackberry browser. $30 6GB data plan is the best deal right now.
Where are you seeing that?
The only thing that even comes close is the $100 plan which only gives you 3GB:
$100.00 /mo.
All smartphones
450 local minutes
100 bonus local minutes
3 GB
Personal email
Instant messaging
Internet browsing
Tethering8
Unlimited sent and received text messages1
Call Display
Message Centre