Consumer Reports has no financial relationship with advertisers on this site.You don't have to spend a fortune to get a good night's sleep.You can order a queen-size foam mattress online for as little as $235 and have the bed-in-a-box delivered to your doorstep, whether that's a shaded porch in the suburbs or a college dorm room. Though these inexpensive mattresses aren't at the very top of CR's mattress ratings, they compete on performance with high-ranking mattresses that might cost four or five times as much. Consumer Reports tests queen mattresses, the most common mattress size, but if you're looking for a twin or full, you can still rely on our ratings to find the best one for you. "The support level of the smaller mattresses should be in line with the queen-size mattresses," says Christopher Regan, who oversees Consumer Reports' mattress testing.How We Test MattressesIn Consumer Reports' mattress tests, we use real people-petite women and large men-to see how support varies for sleepers of different sizes. (The average score is just that, an average of the two.)With lab equipment and human subjects, we evaluate how well a mattress supports the body for both back and side sleepers, how easily sleepers can shift their weight without disturbing their partner, and how well the mattress keeps its shape over time.For firmness, rather than take a manufacturer's word for it, we measure that attribute precisely for each mattress we test and plot the results on a scale of 1 to 10, with 10 being the firmest. We measure support when the test subjects are lying on their side and again on their back. That makes it easier for you to use our ratings to match your size and favorite sleeping position to the perfect mattress.Inexpensive Foam MattressesBelow are ratings and reviews of eight foam bed-in-a-box mattresses that cost $600 or less. Prices are for queen-size mattresses; the same model in a single or double costs even less.If you can afford to spend more, check our full mattress ratings and recommendations. You'll find bed-in-a-box mattresses from brands such as Amazon, Costco, Ikea, Sleep Innovations, Spa Sensations, Tuft & Needle, and many more, as well as innerspring and adjustable air models.One notable exception to the list below: Casper. The Casper mattress didn't make the grade for this roundup based on price: It costs more than $1,000 for a queen. Casper's Essential mattress, $600 for a queen, doesn't score high enough in our tests to be considered.Tips for Buying a MattressTossing and turning all night? Maybe it's time for a new mattress. On the "Consumer 101" TV show, CR expert Chris Regan shares tips on what to look for when mattress shopping.Consumer Reports is an independent, nonprofit organization that works side by side with consumers to create a fairer, safer, and healthier world. CR does not endorse products or services, and does not accept advertising. Copyright 2019, Consumer Reports, Inc.