use strict;
use warnings;
my $str = "2A2B2C";
my %p = (A => 1.5, B => 2.5, C => 3.5);

my @arr = split/(?=\d+)/, $str;
my $range = 50;
map{s/^(\d+)([^\d]+)$/(($p{$2}."\*") x $1)."$range\/100"/e; $range+=5;}@arr;
$str = eval join'*', @arr;

print $str;