I bought the iPhone 6rg 64gb through jump on demand but I am not sure if the purchase option is right. I am paying $600 including the $100 down for a span of 18 months but if I want to purchase the phone it says I need to pay additional $182 which doesn't include taxes. So is the purchase option too costly? Since the phone price shoots up to $800 or more (because of taxes) if I am purchasing. But the phone is worth only $750