use strict;
use warnings;
use Data::Dumper;

<DATA>;

my @products = keys %{{ map { /^\d+\s+(\w+)$/ ? ($1,1) : () } <DATA> }};

print Dumper(\@products);


__DATA__
price     product
200       shoe
20        shirt
10        shirt
5         hat

##</code><code>##

$VAR1 = [
          'hat',
          'shirt',
          'shoe'
        ];