Sites Storage Space

Sites Storage Space for Standard version - Learn More | Google Groups

Currently if you'd like more storage for your Google Sites users is to
upgrade to our Premier Edition or Education Edition (only for
qualified schools and U.S. non-profits with 501c3 status).

The total space limit for storing files is 10GB PLUS 500 MBs per each
users, for Google Apps Premier and Education Editions. So for example,
a customer with 50 users in the Premier edition, will have 10GB + (500
* 50MB) = 35GB of file storage.