Actual Quantity Discounts With Options

Im sure someone developed and addon to give quantity discounts INCLUDING cost of option

EG, 10+ rate of item each = 1.00

Options added to option = + 1.00

discount is 20% so price including option should be £1.60 (-20% form total including option)

But price calculated by cart is only - 20% from actual product so total = £1.80

Does anyone know where the addon is Ive search marketplace V4.52