How Much would my plan be with the IPHONE 3G ?

[roxylikeapuma55]

I am an add on on my brother plan. We have the family text plan, and I pay them 20$ a month, 10 for the add on, 10 for the texting. If I got the Iphone would I just add 30$ for the internet. Which the grand total for my bill is 50$ ?

Thanks
Roxy