Discounts based on quantities are a standard zen-cart feature. For some reason this has never been implemented in ZenMagick and thankfully the available plugin has taken care of things so for.

As it is the only contributed plugin, I have been very hesitant to integrate quantity discounts into core.

However, I figured I should perhaps do this before too long and though, oh, well, just grab the plugin code, massage it to what my coding/formatting standards are and be done – wrong!

After some research in the zen-cart code I found that there are actually quite a few things the current plugin does not support. First of all, the plugin will do percentage discounts, no matter what type is set up. Also, that discount will always be based on the base price, so specials are not handled properly.

Doh, seems I should have looked at this earlier, but then, no one seems to be affected by this, so I wonder if quantity discounts are actually a more esoteric feature (I suspect that this is related to the small user base, though).

Anyway, the next version will include full support for all available quantity discounts. Again, unit testing helped tremedously to keeo me sane while comparing zen-cart and ZenMagick results.