A good-quality mattress is an investment that gives you the most return. When you are rested, your mind functions better, your memory is sharper, and you can be sure you won't fall asleep on the job, in class, or while driving. For less than the dollar you spend on your daily cup of coffee (or $2.50 at Starbucks), you can get a quality mattress that will last you for years to come, and provide you with the sleep you need to be at your best. So there is no "price limit" on buying a mattress, the way there would be for, say, a car or a stereo. Some mattresses are less expensive than others, but you must be sure they are of comparable quality. See "Count Sheep, Not Dollars" in "Tips for Buying a New Mattress."