Attributes for an article -- remove the other

[Aztek]

Hi everyone,

I'm new on prestashop and blocked on configuring my product, I try to explain what I would like to do:

I have one product that can have 2 kind of attributes, one is expensive, the other is cheap, but the product is only one, the attributes is something that I can add to the product itself, so, for example, if I have 10 products, when I choose the attribute, the other one is automatically excluded, the product go to the shopping cart, and the total amount of product available is now 9 pieces.

I tried to create this two attributes using "Catalog/Product attributes" and add them to the product using the combination, but when it requires the quantity for the product, I have to add the quantity for each attributes and not only for the product itself.

 

Is it possible to obtain what I need and how?

Thanks a lot for you help!