def getTotalPrice(self):
        """ compute total price """
        price = self.getPrice()
        price = Decimal(price or '0.00')
        vat = Decimal(self.getVAT())
        vat = vat and vat / 100 or 0
        price = price + (price * vat)
        return price.quantize(Decimal('0.00'))
compute total price