Does anyone have any experience with knowing how much MB usage is billed to use the WDW Park App with Verizon.

I currently have no data service on my phone, so I am going to add a data package just long enough to use the app on my trip.

I am trying to decide whether 25MB for $9.99 would be enough, or if I have to pay for unlimited usage.

I would just pay the unlimited rate for one month and be done with it, but my trip spans two billing cycles with Verizon, so I am afraid I may have to pay for a package for TWO months because of the split billing cycle, and paying for unlimited data for two months might change my mind about using the App.

Has anyone went for a week and used the app for under 25MB, or is that a hopeless cause?