If you want to drive yourself nuts, go shopping for a new mattress. You'll hear dozens of theories on coils, fabrics, stuffing, foam density and warranties.

What I know about buying a mattress I've learned from the best — insiders who are now retired from the sleep-products industry.

CONFUSION FACTOR. All of the major brands, like Simmons, Serta and Sealy, make decent mattresses. But if you're planning to go from one chain store to the next comparing prices, forget it. The major brands change the names of the mattresses for each store, so it is impossible to compare mattresses by make and model.

SHOP BY LEVEL. Each company makes levels of mattresses: very cheap, decently cheap, good and best. That's not what they call them, but you can tell which level a mattress is by the pricing within each manufacturer's line of products. Expect several models in each price level.

PRICE MATTERS. You get what you pay for in a mattress. A very cheap mattress is about 10 percent materials (foam, steel, padding) and 90 percent air; a mid-level mattress is about 40 percent materials; and so on. The more material, the better the product and the higher the price. A high-quality mattress will be up to 90 percent materials, and therefore the heaviest. You can lift a mattress to determine its quality.

WEIGHT MATTERS. The heavier the sleeper, the heavier you want the mattress to be. A lightweight mattress will do just fine for a 50-pound child or in a guest room that is seldom used. But for heavy adults, opt for the heaviest mattress you can afford.

TAKE A NAP. Once you've narrowed your selection to two or three, take a nap. Spend at least 15 minutes on each of the beds you are considering. Comfort is key here, so don't make a hasty decision.

RETURNABLE. Make sure there is at least a 30-day trial period. This is a deal-breaker, and you should absolutely not purchase a bed without this guarantee, no matter what else the store is offering. Most beds require a few weeks of sleeping to discover how they will feel long-term. Don't give up on a new bed after a few bad nights. Your body has to adjust to it.

TRUST THE CLUBS. Warehouse clubs like Costco and Sam's Club carry a limited choice of name-brand mattress sets in all sizes. They're typically top of the line for cut-rate prices, but you won't have a salesman to consult (perhaps that's a good thing), and you won't be able to take a nap. That said, I can say from personal experience that both Costco and Sam's Club make wise choices and have generous return/refund policies. Trust them, and you'll knock hundreds of dollars off your mattress cost.

CONSIDER ONLINE. There's a new trend toward low-priced high-comfort mattresses that you can order online and have sent your doorstep rolled up in a box that is lightweight enough to easily maneuver up a narrow staircase. I know it sound ridiculous, but it is the new wave. The thousands and thousands of very happy customers can't all be wrong. Companies like Tuft & Needle, Leesa and Casper are getting thousands of rave reviews. All three of these companies have a 100-night guarantee with free return for a full refund, no questions asked. Given the customer feedback and the amazingly low prices, I think it's worth considering a mattress you can't test in a store — but only if you have nothing to lose for trying and you will carry through with a no-hassle return if it's not right for you.

Mary invites questions, comments and tips at [email protected], or c/o Everyday Cheapskate, 12340 Seal Beach Blvd., Suite B-416, Seal Beach, CA 90740. This column will answer questions of general interest, but letters cannot be answered individually. Mary Hunt is the founder of www.DebtProofLiving.com, a personal finance member website and the author of "Debt-Proof Living," released in 2014. To find out more about Mary and read her past columns, please visit the Creators Syndicate webpage at www.creators.com.