Pitfalls of Low Prices at the Pump

I went to the Gas Station tonight to "fill up." I feel so smart for waiting until now to get gas because it has dropped from $3.75 pg in my neck of the woods to $2.70 pg in about two weeks! Now, it is important to understand that I live by a strict budget. I rarely spend beyond what I have written on paper to spend, but as I pulled up to the pump tonight I found myself wanting to spend more than I had budgeted. "Gas is so cheap!" I rationalized. "I should fill up now before gas prices return to their homes in the clouds!" But wait...why should I spend more to save more? I didn't plan to spend that much, so what does it matter if the price is lower. I should be thankful for the bargain--I get a little more gas tonight for the meager sum i had allotted.
Then I got to thinking about how easily we fall into the pitfalls of consumerism. That is, we buy more when we have the opportunity to be saving more. Wal-Mart encourages us to buy a colossal size bag of chips at 24cents per oz instead of the all-we-really-need regular size at 35cents an oz. Maybe other people aren't like me. I tend to eat more chips or use more gas when I have more. Either that colossal size bag won't last me any longer than the regular size, or I won't be able to eat them all before they get stale. On the one hand I get fatter, and on the other I waste my money.
Getting back to the pump I realized that all the gas I needed was what I had budgeted for. Not only that, I felt good about myself for sparing the environment some carbon, and also my car for not putting extra miles on it. Moderation is the key. This is nothing new--I think Ben Franklin talked about it--but it bears refreshing.