I also have the same problem with pricings,
i want to make it posible to have a group discounts based on categories, so once when i select category admin that every category have discount of it's own per group.

somebody hava a answer?

i also extracted this price per group discount patch and installed it on my cart manualy, extracted filles will be in downloads soon i hope, think it's match more easier to install it this way!

anyway it's quite good module, and instead on categories it has discount on products, it's cool, but it's only 4 groups.
and there is no percentage discount on groups, maybe somebody knows how to change that you dont need to calculate the price for group A or group B, instead you just enter percentage discount for certain group?