Better bundle discount support (1+1, 2+1 gift, etc)

[AndreiMaz]

We should allow a store owner to configure bundle discounts. For example,

• Buy 2 and get 1 (or 2) gift
• Buy product A + product B and get X% OFF
• Buy 2 product A and get X% OFF
• Buy 3 and get X%
• Buy 5 and get X%
• Buy 2 product A + 1 product B by $X
• What else?

All such discounts (bundles) should be configured on the discount pages (like we already do for other discounts)

And when we configure such bundles, our customer should know about it. So we have to display it on the product details or shopping cart pages

[PanagLtd]

In addition to bundling there are many other types of discounts that are not possible. For example, a common situation on Fashion shops is discount by categories where 1st item is 20% 2nd is 30% and 3rd is 40%. This kind of discount is impossible to produce today.

I created a plugin that overrides core functionality of nopCommerce price and shopping cart calculations to enable this.

But, I think we are missing something in the Discount area. It would be great if we had the possibility to make "discount calculation plugin" in addition to "discount requirements plugin".

Discount requirements allow us to enable/disable discounts base on some conditions. But the discount itself has very basic features (by % or by amount). I would like to be able to extend discount calculation types so store manager can choose what kind of discount calculation he wants in addition to the requirements..