$cost = $h->{Locations}{$location}{Buildings}{$b}{cost};

##</code><code>##

$cost = $h`Locations`$location`Buildings`$b`cost;

##</code><code>##

$cost = $h->{Locations}{$location}{Buildings}{$b}{cost};

##</code><code>##

$cost = $h{'Locations'}{$location}{'Buildings'}{$b}{'cost'};

##</code><code>##

$cost = $h«Locations»{$location}«Buildings»{$b}«cost»;