Mixed shipping

Hi, I'm sorry if this has been answered before.
I need to setup the following rules:
Some of my products have $12 shipping price PER ITEM.
Some of mt products have $15 shippong price PER ITEM.
All other products cost $12 for batches less than 5 pieces, and $20 for batches more than 5 peces, PER BATCH, not PER ITEM.

If i order 3 items of the first group and 5 of the third group the shipping should be 36 + 20 = 56.
Thanks for the help in advance

You will need some definite customization to manage this kind of shipping ...

If you are not a coder, you may wish to post the details of what you need in the Commercial Help Wanted to get a customized shipping module made for you ...

Wow, that was fast :)
I am a coder, I am doing this for a client, but I was hoping that there is a configuration technique to avoid hacking into the code since I've never worked with zen cart before.

What do you recommend I do/read ?

I have zen cart 1.2.5 installed and I applied the perunitweight shipping module as instructed in the other threads.

You realize v1.2.5 is older than the hills and so buggy you do not even want to think about it or your head will hurt ... :eek:

I thought about the Per Unit perweightunit shipping module too, as the first choice ... then you went into the gang pricing on some products ...

If you got rid of the $XX for 5 junk or had a way to know when to do this and got the count for those products to calculate the separate charges then added them to the amount charged by the products_weight in this module then you could use that as the starting point ...

I was thinking of making some weights 12, some other weights 15 and all other weights 0.01. That way I could apply table-based shipping on orders with less than 10 on weight (i can safely assume that no one will ever make an 1200 items order ), but the problem is with mixed carts.
Can I at least disallow mixing certain products in a same order ?
thanks for your help.