Okay, I am about to be very vulnerable and share something about myself that may make some people laugh in scorn. But I believe, based on 1 Cor. 10:13, that I am not alone in struggling with anything; therefore, somebody out there will benefit from what I’ve learned. So, if you find it tempting to go to several different stores to buy your groceries (anything, actually) because the sticker price on an item is cheaper at another place, then this little series is for you!
I’ve been re-reading Mark 9:33-50 lately, and verses 43-47 have me once again examining my life for anything that needs to be “cut … off.” A commentary on these verses helped me to see this teaching of Jesus in a new way—a way that makes it applicable to more aspects of life than just the most obvious and horrible sins. It’s possible that even in our attempts to do good (like saving money), we can unwittingly fall into a temptation that sabotages our efforts (wasting time and money on gas)!
So, as I contemplated my life (habits, etc.), the Holy Spirit brought to mind my grocery-shopping routine. I’ve spent far too much of my life having to pinch pennies, so I’ve closely watched the price tags and gone to several stores in pursuit of the lowest price.
When is it worthwhile to go bargain shopping?
Unfortunately, grocery stores tend to be spread out. Yet, I never before gave a second thought to how much extra time and gas I was spending to save a few pennies! Okay, maybe I did have a few fleeting thoughts about it, but I didn’t know exactly how to determine if I was truly saving or wasting. I heard people mention that chasing the lowest sticker price around town wasn’t worth it, but they didn’t give any details about how to figure that out.
So, when is it worthwhile to go bargain shopping? How much cheaper must the price be to make it worth the time and gas to get an item elsewhere?
The answer is found in calculating two numbers: the cost of gas and the cost of time. Once I crunched these numbers for myself, I was shocked at what they told me!
The Gas-Cost Formula
First, find out how much it costs you in gas to go to each store from your house. You need to know
1) the distance from your house to each store,
2) how much the gas in your tank costs per gallon, and
3) how many miles per gallon your car is getting.
Discovering the distances can be easily found out by using a map app. Just ask your smartphone or computer assistant, “How far away is the nearest [store name]?” Write down the miles it tells you for each store. Also, write down the travel times provided; you’ll need this info in Part 2.
Pull out your latest gas receipt to get that price. This is the one piece of data that will change over time, so if you want to have the latest, most accurate data, you will want to recalculate this with every fill-up. Some of us will feel the need to do this recalculating, while others won’t; do whatever helps you feel confident that you’re wisely deciding about where you’re shopping.
Next in this first formula, you need to know how many miles per gallon your car is getting. If your car is like mine (2009 Honda Cr-V), then the dashboard computer system should have this number readily available for you. If not, then you’ll need to pay attention to the difference in your odometer from one fill-up to the next fill-up, and divide that number (of miles) by the number of gallons your car tank holds. (Yeah, thank God for these car computers that figure this out for you!)
Now that you have the price per gallon of gas and your miles per gallon, simply divide the price by the miles to learn what one mile of gas costs you. Example: gas is $2.23/gallon, and the car gets 20.3 miles/gallon; 2.23 divided by 20.3 equals 11 cents/mile.
Once you have your gas-cost per mile, multiply this number by the miles to each store, individually. Example: Store A is 1.6 miles from home, so 1.6 miles x 11 cents/mile = .176 (18 cents) one way, or 36 cents round trip. Store B is 2.8 miles away, so 2.8 miles x 11 cents/mile =.308 (31 cents) one way, or 62 cents round trip. Do this for all the stores you might shop at.
While the cost in gas to go to any store might seem extremely cheap by itself, it becomes humongous when you realize that the sticker-price difference between Store A and Store B must be greater than the cost in gas to get to Store B before you really save any money!
The sticker-price difference between Store A and Store B must be greater than the cost in gas to get to Store B before you really save any money!
Here’s an example for more clarity. Milk at Store A costs $2, while Store B has it for $1.97. Store A is closer (1.6 miles) but costs more, while Store B is cheaper yet farther (2.8 miles). The price tag difference is only 3 cents, yet every single mile of extra driving is costing you 11 cents!
Clearly, you are already paying more in gas just to chase a 3-cent savings. But we haven’t even calculated what it’s costing you in time! So, if the gas cost alone isn’t enough to influence your shopping habits, be sure to read part 2.
Thanks for reading!
 Vernon D. Doerksen, The New Testament Study Bible: Mark, vol.3 of The Complete Biblical Library, internat’l ed. Thoralf Gilbrant (Springfield, Mo.: The Complete Biblical Library, 1988), 261-5. If God will help me be succinct, someday I’ll write a more spiritually-oriented blog about this hyperbolic teaching, explaining my understanding of it in greater detail. So, keep watching for that!