Just got 2 boost phones, Got a quesion.....
The only one that got me was the Internet charge -- I misread the site and thought it was $0.20 per day you use the net. Turns out, once you use the net even once, after that you're charged $0.20 a day from the on.
There are no 'hidden' charges that I've seen in the month and a half I've had Boost.
You can always click the 'My Account' link at the top of the page, log in, and see every charge you've ever incurred, which is NICE.
Yachris is right on the mark..the only other possibilities for "hidden" charges would involve international toll charges if you make a call to an international number or if you were close enough to the border, Canada or Mexico and you handset attached to a tower outside of the Nextel/Boost footprint....rare, but I have seen it happen.
Also please be aware of getting drawn into "subscription" applications via your Wireless web...chat rooms, instant messenger, joke of the day type crap is a drain on your funds and is often tough to get these third party leeches to stop.Let us know if there is anything else we can help with !