JMS quantity related price is a specialized plugin that allows you to set the price in the component Virtuemart, and configure them so that your customers when buying multiple identical products were able to obtain significant discounts.
JMS quantity related price plugin for Virtuemart

JMS quantity related price plugin for Virtuemart

In the standard set Virtuemart was not provided the opportunity of flexible adjustment of prices for purchasing several goods simultaneously, therefore and created this wonderful plugin. Its effect is this: your customers put the product to the cart, or simply choose some number of products or services, while visually changing their value. But the cost changes dynamically – depending on the specific configuration, for example, if you select 4 or 5 items, the potential buyer receives a considerable discount.
Advantages
Support Joomla 2.5 and Virtuemart 2.0-2.6
Modifying and applying the rules for products and categories, suppliers, etc.
Support unlimited number of products to set prices.
Supports multiple operation type + / – / +% / -%