After all, the older you get, the more valuable your time seems. And going to Costco, even though it’s just a couple of miles from my home, is generally a two-hour round trip by the time the driving, the shopping, the waiting in line, the loading of the car and the unloading back home are done.

In 2007, meanwhile, Amazon.com introduced a service called Subscribe & Save. The premise is simple: If you agree to get a recurring shipment of an item, Amazon will cut 15 percent off its normal price and send it to you every one, two, three or six months without charging the standard shipping rate. So I subscribed to toilet paper, which makes for a great story and good fun for children when three months’ worth arrives and become a temporary tower or a fort on the living room floor.

Ever since the toilet paper subscription (and later, the paper towel one) started coming, I’ve wondered what it would be like to subscribe via Amazon to everything I get at Costco and never set foot in the place again, except to cash my check each year.

So this year, $304.50 refund check in hand, I went to Costco with a list of items that most households need to replenish every so often. I recorded the prices. Then, I compared them with identical items at Amazon, looking in particular for the ones among the 40,000 or so that are now available for subscription.

My guess is that many Costco customers would find that any savings they gain by shopping there is eliminated and then some when they consider the value of the time spent going to and fro many times a year. That’s time they would win back if they subscribed to those same items at Amazon and then never had to think again about running out of them.