It is possible to setup the account state scenario to say only dollar values rounded.
The available settings for the up_rounding_threshold parameter are between 0 and 99 it means the hundredths parts of amount.
If the hundredths part is higher or equal the up_rounding_threshold parameter it will round up if its lower then it rounds down the value.
Account state is 7.50 - if the up_rounding_threshold="50" is setup like below then voipbox will play : 8 dollars.
Account state is 7.49 - if the up_rounding_threshold="50" is setup like below then voipbox will play : 7 dollars.
Below is the modified account state scenario.