Coupons and Quantity Discount Combinations

I'm setting up online wine sales for a winery. The quantity and coupon discounts are sort of complicated, and after a bit of time working on this, I'm not seeing a way to make it happen.

Essentially I don't want the quantity discount to apply if a discount coupon is used. There is a base 10% case discount, which needs to go away if for example the industry discount coupon (30%) is applied.

Any idea on where to start tweaking for this?

Thanks
Matt

The problem is right now that the Products Qty Discounts will show in the shopping cart ...

Then, when the Discount Coupon is used, they would disappear ... based on custom code to stop the Product Qty Discounts when a Discount Coupon is used ...

This would probably tick off a lot of customers and cost you sales ...

Matt, if you use the Quantity Discounts contribution (not the native Zen Cart Quantity Discount), you can apply the discounts only if no coupon has been used. And since these discounts are not seen until checkout time, the scenario Ajeh is describing would not happen. Click Quantity Discounts in my sig to read more about it.

Good luck,
Scott