sub rate {
   return 50 if $_[0] eq 'basic';
   return 150 if $_[0] eq 'bronze';
}

$rate = rate($package);

##</code><code>##

my %rate = (
   basic  => 50,
   bronze => 150,
);

$rate = $rate{$package};

##</code><code>##

{
   # %rate is private to rate().
   my %rate = (
      basic  => 50,
      bronze => 150,
   );

   sub rate {
      return $rate{$_[0]};
   }
}

$rate = rate($package);