my %price = (
    1 => {
        1 => {
            name   => 'Early Adopter',
            price  => 3.49,
            stripe => 'price_123245',
        },
        6 => {
            name   => 'Early Adopter',
            price  => 18.99,
            stripe => 'price_123267',
        },
        12 => {
            name   => 'Early Adopter',
            price  => 32.49,
            stripe => 'price_123289',
        }},
    2 => {
        1 => {
            name   => 'First Increase',
            price  => 3.99,
            stripe => 'price_123445',
        },
        ...

##</code><code>##

Multidimensional syntax $price[1,1] not supported at 1.pl line 6.

##</code><code>##

my $gbp_sum = $price{$plan}{$length}{price};