Prices go up and down all the time.
"Supply, demand, the price of raw materials, the price of gas, location, the economy — it all affects product pricing," explains Yahoo tech columnist David Pogue in his 2016 book, "Pogue's Basics: Money."
While that's entirely out of your control, what you can control is when you shop. "In certain industries, the prices for products always drop at certain times of year, like clockwork," Pogue writes.
He provides a cheat sheet for the best time to buy just about everything, from electronics to gym memberships. Here, we've highlighted 17 essentials and the best month of the year to buy them.
Fitness equipment: January
After the holidays and when New Year's resolutions are still in force, stores will start to lure customers in with sales, Pogue writes. Expect "huge deals, from 30 to 70 percent off."
Cruises: January and February
"Sales on sailings usually arrive in January and February, when people are booking their spring break and summer cruises," Pogue explains.
If you're planning a holiday cruise, look for another round of sales in October, he writes.
Specifically, camera shop over President's Day weekend, Pogue says: "New models usually debut in February, so you can count on big discounts on last year's models on Presidents' Day weekend."
Right after Valentine's Day, you can find even the fancy stuff cheap, Pogue says.
New luggage styles arrive in March in anticipation for summer travel, so you can find great deals on last year's suitcases. Plus, with Spring Break coming up, it's the perfect time to snag a new duffel.
"In August, another round of price cuts settles in, since people are pretty much finished with their summer travels," Pogue writes.
Cookware: April and May
Graduation and wedding seasons are fast approaching, meaning you'll find good deals on kitchen supplies — particularly over Memorial Day weekend, Pogue notes.
Memorial Day mattress sales are a real thing, Pogue explains: "The entire industry blows out last year's models over Memorial Day, so watch for crazy sales in May."
If you miss out on this specific weekend, don't stress — more sales will come around over the weekends of July 4 and Labor Day.
Gym memberships: June
"The best deals, logically enough, sprout in June," writes Pogue. "That's when demand is lowest, as people head outdoors for physical activity."
Valentine's Day is long gone, and there are no gift-giving holidays around the corner to boost stores' sales.
Capitalize on the lull. You could even knock out a few Christmas gifts and have one less thing to worry about when the hectic holiday season rolls around.
Bathing suits and flip-flops: August
Swim season is officially over and stores don't want shelves of swimwear that no one is going to buy, Pogue says.
Snag them on clearance now … or pay much more right before heading out on a spring trip.
Camping gear: August and October
Take advantage of giant price cuts on outdoor essentials in August, advises Pogue: "The summer's over, and so is demand for this stuff. Look for another rash of sales in October, too."
If you're in the market for a new computer, wait until the back-to-school rush is over and buy one in September, Pogue advises.
He also notes that there will be more discounts in November, on Black Friday and Cyber Monday.
If you need a new ride, you'll get the best deal in September, says Pogue. It's the start of the model year and dealerships will be eager to clear last year's inventory.
Bicycles: September and October
New models start coming out in these fall months, meaning it's a great time to snag a sale on last year's bikes, Pogue explains.
Specifically, right after Halloween. "Every store and its brother slash prices to unload all the unsold candy," Pogue writes.
Your options may be slim, but the prices will be hard to beat.
The hype that electronic stores get for Black Friday and Cyber Monday discounts isn't unjustified.
"Every category of gadget goes on sale: TVs, laptops, phones, tablets, cameras, and so on," Pogue writes. "Every store and online retailer fights for headlines, and the winner is you."
Wedding dresses: November and December
Even if the big day isn't until the spring or summer, start looking in November for a more affordable gown.
"Nobody's buying wedding stuff in November and December," Pogue explains, "so that's when the bridal shops mark down their wares to make room for the new year's designs."