Hi,
I am writing a plugin to extend virtuemart. The requirements of the plugin is to modify product cost price at the top of the tree above all other processes but after the db query.
In other words what should the plugin extend?
VirtueMart 2.6.12
Joomla! 2.5.27
vmcalculation. But maybe I wrote already what you need http://extensions.virtuemart.net/products/quantity-related-price-calculation-detail