Numrange can be used to specify that results contain numbers in a range you set. You can conduct a numrange search by specifying two numbers, separated by two periods, with no spaces. Be sure to specify a unit of measure or some other indicator of what the number range represents.
For example, you might conduct a search for DVD player $250..300 or 3..5 megapixel digital camera. Numrange can be used to set a range for everything from dates (Willie Mays 1950..1960) to weights (5000..10000 kg truck).
Or you could negate the string to filter OUT results that include prices. Good way to find reviews on a topic?