When you're living from pay cheque to pay cheque is easy not to think about the long term. After all, you're just trying to make it through to the end of the day. So when it comes to day-to-day shopping chances are you'll buy exactly what you need, and that's it. So if there's a sale on something that will give you a little more product for your money, you'll turn a blind eye and miss out on a good long-term deal.