BlogVault can easily backup a website as large as 350GB. BlogVault servers are used to run the backup processes and for storage.
We typically expect a site to use up to 5GB of space. However, if you have a larger site, please let us know. If it is for fair use, we will make an exception (at no additional charge). BlogVault works well with very large sites, and currently supports customers having sites spanning 20+ GBs of data.