Following last year’s news that the trade war with China had raised prices of washing machines, consumers were understandably leery of making any sudden purchases.

The escalation of tariffs has carried over into 2019, and the confusion around buying home appliances is still very real.

With some models costing upwards of $1,000, purchasing a washer is no minor expense. That makes finding the right machine just as much a matter of saving money as it is about cleaning your clothes.

NerdWallet tracked prices on a handful of washing machines for nearly a year to help shoppers identify the best possible deal, and the findings were surprising. Here are the three things you absolutely must know before buying a washer.

1. Search by model number

We checked prices weekly on nine different washing machines at seven different retailers from February through December 2018.

We soon realized a troubling trend for consumers: The same model would often sell for vastly different prices at different retailers on the exact same day — in some cases a difference of hundreds of dollars. What could possibly explain the price discrepancy?

“Sometimes retailers are able to buy really large quantities of stuff,” says Lars Perner, an assistant professor of clinical marketing at the University of Southern California.

“So they get a large price break if they buy two or three times what they might otherwise buy of a particular model. Then they can pass on some of the savings to the customer.”

That’s one possible explanation for how one store can charge you considerably less than another store for an identical product.

In our research, in late March 2018, a Samsung AddWash washer sold for $799 at Sears, $999 at Home Depot and $1,099 at J.C. Penney — all on the same day. Consumers could’ve overpaid by as much as $300, depending on where they shopped.

Similarly, in mid-June of last year, a Whirlpool top-load model was listed for $1,169 at Lowe’s, but it was $1,399 at Home Depot on the exact same Friday. That was a $230 difference between the two home improvement giants.

The takeaway? When shopping for a washer — or any appliance, for that matter — refrain from making a purchase at the first store or website you visit. Always search by model number to compare prices at more than one retailer before deciding where to buy.

You can usually find the model number (often a combination of numbers and letters) listed in the product description. Copy and paste this number into Google or directly into a retailer’s website. You may be surprised by the price difference you’ll find.

2. Ignore most other numbers

Aside from the sale prices, our price-tracking exercise revealed lots of other confusing prices.

Some retailers listed a washer’s regular price or previous price alongside the sale price. Others would provide the product’s MSRP, or manufacturer’s suggested retail price, as a point of comparison.

For instance, in September, a Maytag washer was available for $699 at Lowe’s. The store contrasted this price with the model’s $899 MSRP. Over at Best Buy, the same Maytag model sold for $699.99, and the store told consumers the washer “was $809.99.”

While shoppers at both stores paid nearly the same sale price, the amount of the discount seemed larger at Lowe’s ($200) than it did at Best Buy ($110).

Before you let these figures sway you, keep in mind that the final sale price — the amount you’ll actually be paying — is the only number that really matters.

Historically, MSRPs have been higher than the price many retailers actually sell the item for. So when retailers have charged less than the amount the manufacturer suggested, they could tell consumers they’re “selling below retail,” Perner says.

3. Get your timing right

We saw washing machine prices go through a spin cycle throughout 2018. A GE model that sold for $497.70 at Home Depot in February was up to $719.10 in April, down to $597.60 in May and back to $719 by December.

If you’re trying to time your purchase, Perner points out a few annual periods that are usually good bets for appliance deals: Memorial Day in May and Labor Day in September.

A new full-sized washer is generally on the market for about two to five years, according to Mark Allwood, senior market analyst at Consumer Reports.

It’s often difficult for consumers to discern the model year of a washing machine, unless it’s explicitly listed. And unlike in some other product categories, a newly released washer isn’t always superior.

“It’s not necessarily best for consumers to buy the newest model,” Kimberly Janeway, home and appliances writer for Consumer Reports, said in an email. “In fact, the best deals and sales are usually on models that have been on the market for a little while.”

Janeway notes that manufacturers aren’t introducing new features as quickly. She said the water and energy efficiency on a new model is close to the same as one manufactured five years ago.

It’s likely in your best financial interest to track a model that you’ve seen on the market for several months, or even a year or more, and wait for its price to drop around seasonal events and holidays. Of course, when tariffs are in play, keep a close eye on possible price increases.

These three tips are tailored to washing machines, but the same savvy shopping mindset can be applied to any major purchase: Do your homework before you buy.

More From NerdWallet

• These 3 Tricks Can Help You Shop Less
• You Got the House! Now, How Do You Afford to Furnish It?
• How Being Neighborly Can Save You Money

Courtney Jespersen is a writer at NerdWallet. Email: [email protected]. Twitter: @CourtneyNerd.

The article Washed-Up Deals? 3 Must-Know Tips for Buying a Washer originally appeared on NerdWallet.