Custom Shipping Charges w/ eCart
We ship a number of large-sized packages from our online store. These packages incur additional handling charges from UPS that do not show up in the automatic shipping quotes provided in PS3 by the UPS API. We own eCart 5, and would like to add a custom shipping charge to our store on a per-item basis.
Ideally, we would like to add a checkbox or field to the item update page in the Admin section, so that our staff can enable these additional handling fees only for the items that require it.
Any ideas about how to get started doing this?