We are considering a some free items with purchases for Black Friday. These will be tiered based on amount spend. I was testing the Add-on product price group which almost fits the bill. I can create the subtotal range but wanted to give them the choice of 2 or 3 items in each tier so I created them as attributes of the product (ie 'Product' for Tier 1 is actually 4 products represented by attributes). The product is correctly added but even though the attributes are required the missing attribute screen is not fired. Is there a way around this or some other low tech solution -this might be a one time thing for us as our business isn't really geared to impulse buying but we figured we'll test the waters.