Quality vs Quantity
You can either buy a more expensive product that will last extremely long, or buy inferior quality goods that you'll need to replace every few years. Also, don't forget to account for brand price when deciding on a product.
More expensive often just doesn't equate to being better.
Basically, try to calculate a products cost based on the estimated time period you'll be using it. Doing so, you'll be able to see what's truly cost effective. It also might motivate you to buy something significantly more expensive then you would have otherwise.