Wednesday Whatsapp Challenge - Do you have to give back the comic that you purchased for only $5?

You purchase a comic book for $5. You do some research and discover that it is worth $100. You go back to purchase 4 more. The seller wonders why you are purchasing so many of the same book and does research and realizes the true value. Does the seller have a right to demand you give back all of books for $5 each? Perhaps just the last 4 (and not the first) since he did not know the true value of what he was selling but you knew what you were purchasing and taking advantage of his ignorance? Explain. This is a tough but fun one… a good way to end the semester !