A couple of money-saving tips:
1) If you really want to aggressively save money at some point, my tip is always sleep on any non-essential purchase, no matter how small the amount. If you still really want it the next day, sleep on it again. If you still want it on the 3rd day, buy it. But you'll be amazed how much you don't buy using this method..
Usually there are none left the second day because the price was just right on the first day.
However: that'll just mean you save that much more (or will have to pay the full price for the item).