My friend bought a subwoofer from another friend which was almost new, but his amp was too powerful and it bottomed out when he played it. He is buying a new sub that has more watt capacity and wants to sell me the one that bottomed out. It is a 10" kicker sub that is 150 watts. I don't know how long he played it for while it was bottoming out. He is only selling it for $10. My other friend said he thinks it's broken but the seller said it works fine. What should I do?