Answer:
The answer is: Yes
Step-by-step explanation:
The court will rule in Sarah's favor simply because Mark's check bounced and no payment was done. Writing a bad check and knowing you didn't have the funds to cover it, is a crime (fraud).
Mark can argue that Sarah deceived him into believing the painting was an original Van Gogh, and that the price should be different. But even if they negotiated a new price, he still has to pay Sarah at least the fair market value.