i'm wondering if it is possible to have attributes that apply to every product in the shopping cart globally.My products are mp3 music files, but what i'm actually charging for is a licenses to use the file in various ways. and the price depends on the type of use.

Id like the customer to be able to search the song catalog, develop a playlist, like a wishlist or project, that they can come back to and edit, then when they have all of the music they want , they can add it all to the cart and choose the type of usage globally and zen-cart would calculate the cost.

for instance, two people may come to my site and each download the same three songs. One might pay $50 each to use them in a training DVD for new business recruits. the other might pay $2000 each to use them in a national advertising campaign. instead of each of them having to choose the appropriate use attribute three times, id like them to be able to change this attribute once during the check out process

another way to do it besides changing attributes in the cart might be to make the music catalog completely unpriced, but make a mandatory product that the customer must choose. this product would be the license, or "type of use" and it would then just multiply but the number of songs in the cart.

forgive me for thinking out loud, i don't know another way to explain it.

Does anyone out there have any ideas or experience doing something like this? I'd really like to do this in zen cart to keep my costs down. I've gotten pretty good at figuring out how to change the css and copy, but the workings of the cart are a little beyond my reach at the moment. I would appreciate any help,