If your attachments, avatars, profile pictures are all served in the database right now then you should definitely move them to your filesystem to decrease the size of your database. Just make sure to run the database optimize/repair script in the AdminCP under the maintenance menu group afterwards.
https://www.vbulletin.com/docs/html/...rage_db_to_fs1
https://www.vbulletin.com/forum/foru...to-file-system
In my opinion, if the host has a database size limit of (only!) 1GB, you should look into moving to a different hosting company.