The best way to get bargains when buying in bulk

With retailers like Amazon (AMZN) and Target (TGT) going head-to-head with subscription programs -- like having toilet paper shipped to your house monthly -- consumers have the chance save some money. But not everything sold this way is a bargain, according to a savings expert.

Kyle James, who writes the Rather Be Shopping blog, priced out some of the offerings that many families might consider for such programs. What he found might not be what you'd expect: The best deals were for products that tend to be among the hardest to carry home from the store, such as dog food, toilet paper and diapers.

"It was a mixed bag for sure, but there were some really nice surprises," James said. "A few of the bulkiest products are clear winners with the subscribe programs, which was a very pleasant surprise."

That result makes signing up to get such products "major no-brainers if you ask me, especially for busy families." Plus, both Amazon and Target offer free shipping for subscription program orders.

Diaper prices varied depending on size and brand, but were largely comparable to the best deals at bricks-and-mortar stores or slightly less, James found. Even when the store prices were a bit cheaper, he said having the diapers delivered directly to your home made up for the difference.

Same thing with dog food. James cited the example of a 30-pound bag of Iams adult dog food, which ended up at 92 cents a pound from Target's subscription service and 97 cents through Amazon. The local Costco (COST) warehouse store actually beat that price at 86 cents a pound, he said, but only if you buy a 50-pound bag. Buying a small 3.3-pound bag at Walgreens (WAG), in contrast, pushed the cost to $2.27 a pound.

Other products that James rated as good deals to get via subscription:

• Laundry detergent
• Paper towels
• Toilet paper

But he found that those services couldn't touch the per-ounce price he paid at Costco for Cascade Complete dishwashing detergent.

A big plus for the subscription services, which offer thousands of staple items, James said, is that they don't penalize you for altering your shipment schedule. If you already have enough toilet paper, he said, you could simply reschedule delivery for a later date.

Similarly, you don't get penalized for canceling the services altogether. The lack of risk, the convenience of delivery and the ability to get better deals make for a tempting combination, James said.

"I was real skeptical when I started doing my research, but have become a convert and have several friends with busy lives who now swear by it," he said. "I really think it will only grow as the word starts to spread. I firmly believe subscribe programs will be the future."