We once paid a programmer for some custom programming on [url removed, login to view] e-commerce software call PHPCart.com. The custom programming added $10 to the Additional Shipping and Handling if the customer ordered less than 10 items, but only for certain items. The script looks to see if there is a number before the first space in the item number, and if so, uses that item's total in determing the extra $10.
I accidentally overwrote one of the files, order.js. The part of the script that does the counting [url removed, login to view] is in tact, but the part that adds the $10 was overwritten. This project involved fixing the scipt for the overwritten part.