for my setup - i mount my secound HDD to ~/.local/share for bigger datas, so that my /home can stay on the SDD but thats only me.
after all the base user directory is the wrong place for it, look at the xdg standards (cant post links right now)
$XDG_DATA_HOME defines the base directory relative to which user specific data files should be stored. If $XDG_DATA_HOME is either not set or empty, a default equal to $HOME/.local/share should be used.