If you are getting error 13 it is likely that you have attempted to move the database by copying only the .MAX files in the Maximizer data folder. However, you have a large database and you have probably not copied the extension files that are part of the document store. Go back and copy the entire folder contents including any files which weird names (including ^).
If you are buying Maximizer 12 Entrepreneur this is not yet available but is expected to support upto 10Gb of data. The Group edition of Maximizer can also support upto 10Gb of data and the Enterprise edition has an almost unlimited data store provided you have the right version of Microsoft SQL Server.