Ok, so I decided to to it for you XD
Opera Mobile Turbo livescore.com: = 182Kb (9MB in 50 visits)
live score app = 52 Kb (2.5MB in 50 visits)
The app is far more efficient. Sorry to go on and on.
*Sorry, I just re read your post, and realized you were talking about an app, and not the stock browser :F In this case you may want to try out 3G Watchdog. You could use it to monitor how much bandwidth is used when starting, and reloading Live Score.At an estimated guess, Opera saves anywhere from 65%-85% of all data incoming. This can easily result in far more browsing time with such a small data plan.
If you're worried about your data plan, you should definitively take advantage of Opera Mobile. The stock Browser does no background compression, so it's already lost.
Consumers save 27.4 billion USD per year with Opera Mini