All expansions, mine takes 4500mb, it puts nothing in .ini files.
That is using TreeSize.
And now my plug, EQ does not have to be installed, you just copy the files to a new directory, register the expansions and you are ready to go, so backups good, backup a little smaller, cause I haven't done it since PoR.
Screen shots and log files can make it much larger, if you have a ton of those.