I have this problem, if the product has a reduction price, the state tax is applied on the "base price" but not on the "final price", there's a problem with this in the shopping cart because the customer will see the final price with a tax based on the "base price" w/c is quite confusing for the customers to look at. for example: state tax= 6.25%(0.0625) base price = $100 <---- tax is applied here reduction = $20 final price = $80 <-- tax is not applied here upon purchase, the cart is showing 80$(final price) but the displayed tax calculation is $6.25(applied from the "base price") and not 5$(applied from the "final price"), its how its doing now. HOW CAN I MAKE THAT THE COMPUTATION FOR TAX WOULD APPLY FROM THE "FINAL PRICE" instead? Any good hearts in here who can help me???