There is the non-zero cost of keeping two copies of that bit of
information in-sync with each other (and the code).

If I execute "pydoc time" I get a link to the online module
docs.  It's not there when I execute "pydoc time.strftime".
Perhaps pydoc should be modified to always include a link
to the defining module even when the user asked for docs 
for something other than a module.