This patch modifies zen cart to allow 4 groups to added that specify per item pricing as opposed to a fixed discount pricing. 

When implemented the prices on the shopping cart page and product info page reflect the per item pricing if the customer

is in a per item pricing group.

Per item pricing groups must be named "Group A", "Group B", "Group C", or "Group D".

Per discount pricing groups still show the regular price on the shopping cart and pricing information page,

but still reflect the discount at the checkout.

To install this patch simply put the patch into your zen cart base directory and type:

patch -p0 < group_pricing.patch

Then implement the sql changes with:

mysql -D <database> -p < group_pricing.sql

Go to the administrative panel and navigate to Customers->Group Pricing

Add a group with the name "Group A", "Group B", "Group C", or "Group D".

Once the group is added, the Categories/Products page will list a box for you to input the Group A, B, C and D price.

Only groups that are specified and added will show up for group pricing per item.

Any other group name will use the percentage discount as normal.
                                                                                                                                                                                                                                                                                                                                                                