Re: BBM Abroad
What do you mean by "turn off the roaming thing"? What thing?
If you turn data off, you will not be able to use BBM. You will have to have data turned on. And you can't only turn it on for BBM.
BBM messages themselves are only text and should only take a few kilobytes each. If you send and receive pictures or files, then you will use a lot more.
100 messages might be around 300 - 500 kilobytes.
Having said that, 25MB for three months is not a lot of data.