Forgive me if this has been answered before...

I have a zencart installation for a non-profit association (www.iands.org). The cart is used mainly to sell DVDs, audio tapes and downloads of conference proceedings. I need to implement a pricing strategy that:

- has different pricing for members/non members

- has quantity discounts within categories that works like this:
first dvd non members: $25 members: $16
each additional dvd $18 members :$12

I've looked at: Dual Pricing (might work for member vs non-member... if I can figure out how to identify members); Quantity Discounts (pricing strategy seems to be globally applied); Group Pricing (per item) (can't figure out how to download/install the patch)

I can implement the member/non member pricing when quantity discounts are not involved by an attribute (and verify membership offline). But I'm clueless as to how to implement this crazy pricing strategy.

Help?