Is it a standard % based discount, or a new fixed price based on the quantity?
There are basically two ways to do this. You can either update the cart to store all of the information to do the discounting and do complex calculations in the cart to figure out the correct price... or you can use a recordset to store quantity discounts and calculate and update the price column as it is in the eCart.
The technique I suggest usually depends on the complexity and consistency of the discounts. If products have different discounts, different breakpoints for discounts, different number of breakpoints, etc. then the Recordset method is easier because it is more flexible. If you are doing regular % based discounts based on fixed break points, then doing a calculation in the cart is easier so you don't have to create recordsets and update the shopping cart from it manually on the cart page when someone updates a quantity.
