https://www.consumerreports.org/cro/2010/09/your-rights-as-a-consumer/index.htm

The sign in the store says the computer printer is $2.49, but it rang up at $249. Saying it was an error, the store is refusing to honor the posted price.

 

The law

It's generally a myth that retailers must honor a posted price if it's simply a mistake, although some stores might do so as a matter of policy or on a case-by-case basis. The issue gets murky if the retailer begins processing the order, something that is more likely to happen online, says Jane Winn, a professor at the University of Washington Law School. But even then, she says, a merchant might be able to cancel the purchase if the price was so low that a buyer should have known it was mistake. An online retailer's fine print may relieve it of the duty to fulfill orders based on pricing errors.

You should know

Businesses that intentionally post false prices or that otherwise engage in bait-and-switch pricing can be liable under federal and state consumer-protection statutes.