Member/non-Mem Discount plus quantity discounts

[healthylifespan]

Just wondering if anyone knows of a contrib or has thought about doing one that supports Member and Non-Member discount purchases incorporating a quantity discount (such as buy 4 or more and get additional 10% off)?

 

To give the idea, members would get a certain discount (ex. 25% off retail) on all products and additional discount (ex. 10% off) if they purchase in quantity (such as 4-or-more of the same kind product).

 

ex: (Retail Price - Mem Disc. 25%) + (-10% if 4-or-more of the same kind product)

 

Similarly, non-members would received the same discount (ex. 10% off) when they purchase in quantity (such as 4-or-more of the same kind product). However, they do not get the member discount and pay retail prices.

 

ex: (Retail Price) + (-10% if 4-or-more of the same kind product)

 

 

thanks for any suggestions or referrals!