Quantity Discounts With Mixed Attributes, Priced by Attribute

[kgamadia]

Hi all,

Running ZC 1.51, first attempt at a multi-download product, though we have several single-file downloads working fine.

The downloads themselves work great based on the tutorial: http://www.zen-cart.com/content.php?...s-downloadable

However, I am having trouble with the pricing aspect, as one can buy parts or the whole, and the whole as in most cases, is cheaper. I have a test product set up here to replicate what we want to achieve, but at a smaller scale to start. Once I have this figured out, I'll create the real ones with a lot more attributes.

http://www.prohealthsys.com/zencentr...products_id=30
This product is a text book supplement. Teachers can purchase supplements for the entire book at $18, or by chapter at $8 per chapter. Hence, quantities 1-2 will be at $8 each, but for 3, the price is marked at $6 each to achieve that $18 book target. Note that the base price is $0 for the product, and that Pricing by Attributes is selected. I set the "Include in base price when priced by attributes" for the first attribute, as then it shows "Starting at $8" on the product page, which is a nice touch.

I searched the forums and found out that:
- radio buttons are preferred over check boxes, but you can see that in this application, the teacher has to check which chapters to purchase - without, there is no purchase itself. And besides, it isn't a one-of-the-bunch option. It is a choose what you need scenario.
- attribute quantity pricing is not appropriate as we will only ever have 0 or 1 of each attribute selected.
- setting the Price manager should allow for discounting with "Discount Qty Applies to Mixed Attributes"

I set up the Price manager with that above option set to Yes, I added an entry for minimum quantity 3, Discount type is Actual price, and I entered $6 for the value. I have the "Priced by Attributes" option set to Yes there too. The sample shows a proper $6 x 3 = $18 sample calculation. And when you look at the product, the table shows the quantity discount option very nicely.

The product LOOKS exactly like we want. However, if you tick all 3, the price added to cart is $24, not $18. Obviously, adding 1 or 2 works fine, since no discounts are expected.

Screen shots below of the Attributes controller page, the price manager, the product displayed, and the cart.

Any ideas what I am missing?

Thanks in advance,

KG
EDIT: Apologies for the images - I expected them to show as thumbnails like I saw in the other forum posts I read through (and they do in the post composition window), but they go away once I save the post.