Perhaps you can take some inspiration from one of the shopping cart frameworks, such as Handel.
A program should be light and agile, its subroutines connected like a string of pearls. The spirit and intent of the program should be retained throughout. There should be neither too little or too much, neither needless loops nor useless variables, neither lack of structure nor overwhelming rigidity." - The Tao of Programming, 4.1 - Geoffrey James
Maybe you can interview the folks at Ticketmaster? While they are reviled by some for allegedly employing tactics such as scalping, venue exclusivity deals etc. to drive ticket prices up and venues out, they are a Perl shop and seem to be largely successful.