#!/usr/bin/perl

use strict;
use warnings;
use List::Util qw/min/;

my $sellable_products = {
    one => 1,
    two => 2,
};

my $lowest_price = min values %$sellable_products;
my @cheapest_products = grep { $sellable_products->{$_} == $lowest_price } keys %$sellable_products;