Blogger > Settings [in-left-sidebar] > Other > Blog tools [page-section] > Export blog > Download Blog > Save File > Save > Close
662 KB (for a blog with 62 posts)
Which appears to contain:
each post -- but line breaks in raw html are not preserved.
Since blogger will probably never disappear, it's probably good enough, but it would be nice to have a backup of the raw html as shown in the html editor, or in fact as shown when viewing source. As described here, that can be achieved via http://blogname.blogspot.com/search?max-results=1000 and the DownThemAll firefox plugin.