Display cart rules like catalog price rules

[MissV]

My client, UST Glass, wishes to offer quantity discounts based on total number of products with mix-and-match capabilities, from 15 categories.

 

Discount 1:

From 1-14 cases is 40% off the List Price
 

Discount 2:

From 15-49 cases is 46% off the List Price

Discount 3:

From 50 cases is 55% off the List Price
 

I've tried using both Cart rules and Catalog price rules. 

 

We want to use Catalog price rules because it displays the correct Unit Price in the shopping cart summary and cart block, because it shows the price with the discount included.  And it shows the 1-14 Case price on the product detail page.  See attached screenshots.  We want this type of display but using Cart Rules so that the discounts are applied correctly since Catalog Price Rules do not let us mix-and-match products in categories and only applies the discount to individual products, so I have to buy 50 of one item to get the 55% discount.  This is not what we are after.

 

Customers need to be able to mix and match products in the above categories to get the best price.

 

Here's what I'm trying to achieve:

 

25 x item A

15 x item B

10 x item C
----------------

50 items = 50% off each item

 

Price displayed in cart and on product detail page need to look like the attached screenshots. 

 

How can we display Cart rules in the same manner as Catalog price rules?  Would I be able to make changes to one of the controllers in my override folder??

 

Or, is there a module that will count the number of cases in certain categories and apply the final percent discount to apply to applicable products in the cart?

 

Here's a link to our main Shop page:

http://www.ustglass.com/index.php?id_cms=15&controller=cms

 

Thank you so much for help with this matter.

 

Best Regards,

MissV

Edited April 22, 2014 by MissV (see edit history)