custom quantity by product

[pdmunich]

Hi there,

i need a hack or option to set a fixed quantity by products. we sell coupon codes in bundles so we need the option like this:

product1 - 4 coupon codes - quantity = 4
product2 - 10 coupon codes - quantity = 10

example: i have one product for each coupon bundle - but in case of order buying one time product1 means  quantity is 1 so only one code is prepared by another component.

maybe this example is better: if you will sell energy drinks in 6packs - but the customer should only buy and see the quatity 1 but the used stock quantity is 6 items
price per drink: 1$
price per 6pack: 6$

the core quantity option should be used to change quantity of 6packs - so user orders 2 6packs - stock shows 12 items

so i need an option to set a quantity which is used if a product will purchased.

does any one has an idea?
cheers jan