Comparison shopping is not a new concept but most people only comparison shop for big ticket items and not for the majority of their purchases. Not saving on these small purchases will, on the long run, cost much more. Here's a simple rule:
More exposure to prices will reduce the chance of you overpaying for something.
For something like a dish rack, you can get $40 extra value for 10-20 minutes of searching in a mall, by visiting all the stores that sell this item. That's like being paid up to $250 per hour. That's why saving isn't "saving" - it's accruing wealth. And when you don't accrue wealth, someone else makes their wealth off of you.