Legal Question in Consumer Law in California

Unless the item you purchased has some unique quality or sentimental value to it, you're probably better off taking the refund and shopping elsewhere.

You are probably right that you formed a binding contract, certainly when they charged your card. Mr. Stone is also right, however. How much trouble do you really want to go to, in order to get this particular item at an unintended and possibly unfair price? How much would you spend enforcing the contract? Is the item really that valuable AND underpriced? If it was that underpriced, a court might find that you knew or should have known the price was wrong and not let you take advantage of it. That's the Catch-22 of these kinds of cases. It's not worth pursuing unless the price paid and the correct price is really significant, but if the price paid and the correct price are so hugely different then the consumer should have known it was wrong an not be allowed to cheat the seller for an innocent mistake.