One of the most difficult things for us to set up is quantity breaks for printed materials. Because of the way they are manufactured, printed materials are usually sold in groups. For example 500 or 1000 or 2500 business cards. And as quantity goes up the price per item is greatly reduced.
What would be ideal is to allow pricing sets that can be applied to the appropriate product. For example a business card might be $39.95 for 250, $49.95 for 500, $59.95 for 1,000, $99.95 for 2,500, etc. But a larger 4 x 6 inch postcard would need it's own pricing table, so would letterhead or envelopes. Business cards can ONLY be sold in pre-approved quantities so hiding the conventional quantity in favor of this would be ideal. Having these pricing tables available to override the simple 1,2,3 style quantity would be a dream come true.
I think of it this way, the conventional quantity value could refer to the Set of cards that you ordered, but the table quantity value would be chosen among available options depending on production restrictions.
If that could be accomplished while still allowing optional price bumps (for example Matte Finish + $10, or Rounded Corners +$15) and even going so far as to make them variable depending on the quantity pricing table. For example you might say that if you get 250 cards for $39.95 then the Matte Finish option is only $5 additional but if you get 500 or more it is $10. Ideally it should just be part of the same pricing table, an additional column for pricing points for any option you might like relative to the bundled quantity. Then if an optional feature costs differently at each interval (like bundling for mailing or something) then the pricing can associate accordingly.
I hope that makes sense, I have been in the print business for many years and don't always communicate what we need clearly.