Hi there I am new to Dropbox and just have a question , my storage is full and I am thinking of starting a plan or subscription but as I was just about to when a thought came in my head , might be dumb but I doent know. So when starting a plan is it the amount one time or do you have to pay the amount every month for the storage for example the 2GB plan do you pay only one time or every month just for the 2GB .