Answer: A statement of opinion is the warranty that was associated with this contract.
Here, it is important to ponder upon the fact that Sam decided to buy the painting for $15,000 on the condition that if he found that the painting was worth less than $15,000, Jasper would have to take the painting back and refund Sam.
This indeed makes Sam's purchase validated with a warranty that is known as a statement of opinion. Although , it should be duly noted that the opinion does not make significant impact on the purchase.