Perhaps you want the sum of all values under a given 'cost key' ('68-4' in this case). 
use strict;
use warnings;
use List::Util qw(sum);

my $VAR1 = {
    '153-1' => {
        '19-4' => {
            'cost'  => '6300.00',
            'cost2' => '630.00'
        },
        '135-1' => {
            '68-4' => {
                'cost'  => '300.00',
                'cost2' => '130.00'
            }
        },
        '1069-9' => {},
        '35-1'   => {
            '28-4' => {
                'cost'  => '30.00',
                'cost2' => '10.00'
            }
        },

    },
};

my $cost_key = '68-4';
foreach my $temp1 (values %$VAR1) {
    foreach my $temp2 (values %$temp1) {
        next if !exists $temp2->{$cost_key};
        print sum( values(%{$temp2->{$cost_key}}));
    }
}

[download]

OUTPUT:

430

[download]
Bill

In reply to Re: Iterating over hash to find specific key to sum up the cost by BillKSmith
in thread Iterating over hash to find specific key to sum up the cost by vaitor15

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