when you post a picture from a groups picture album you can do it two ways....click the little yellow square above and click on line photo then select from the list on left , click then select photo and click...that will place the photo in your reply....being it is already in your storage you wont be charged for more....
the other way to post a pic from a groups picture album is to copy and paste and you will not be charged storage...the bottom line is once that photo is in a "secured" site ( msn photo album) you already have been charged storage amt.