At present we do not offer additional space with any of our plans as a standard extra. If you require additional space on a more permanent basis you will be required to upgrade your plan.
Additional bandwidth charges are on a per-monthly basis, with prices varying depending on the type of account you have purchased (view our Shared Hosting and Reseller Hosting plans for more details).
However, if you have already reached the maximum limit possible or wish to bulk-buy bandwidth, please Contact our Support or Sales Teams who will review your request and discuss your requirements. We will consider each situation on an individual basis.