use strict;
use warnings;

# here the code where the $hashref is populated (or maybe it is actually part of a hash of hashes or array of hashes, we don't know enough details)

open my $FH_OUTFILE, ">", "output.txt" of die "could not open the output file $!";

my $price = $hashref->{price};
my $item_name = $hashref->{title};

if ($price >= 55 and $item_name !~ /electric/) 
{
    print $FH_OUTFILE "free_batteries";
}
print $FH_OUTFILE "\n";
# perhaps some code to close $FH_OUTFILE (if you're done at this point)