I've been reading through the forums for a few hours now, and I *believe* I need to be using per-weight shipping on my store, but am really confused. I have tiny items that can ship 10 to a Priority Mail box, so shipping for quantities up to 10 would only need be charged at $4.35.
But then I also have some huge items that would need to ship at $19.95 PER box, regardless of how many they ordered. Am I correct in my understanding that the only way to do this would be to use "per weight" shipping?

To further complicate matters, I also need to figure out how to offer gift certificates with free shipping.

The only shipping system I've ever worked with is Mal's e-Commerce. It has me setting "units" per item, where each unit is equal to say, 10 cents. Then I have to manually assign a number of units per product to get it to calculate shipping for them. It's not a perfect system and doesn't allow for me to give discounts for multiples of the same items, but it comes close to an acceptable rate. Does Zen Cart have these "units", or is there an equal or easier way than what I'm doing?

Please help if you can,
Grandma J