I really need some wisdom and advice. I am a 65 Year Old Retired Teacher with some debts not balanced by income from my pension. I am an Apple nut and have discovered that because of my iPhone, iPad, and MacBook Pro, I seldom use my 27" iMac, late 2009. Last summer, I doubled the RAM. I decided to sell it, buy a much less expensive HD TV to use as a display for my MacBook, and use the the balance to pay some bills. It has been working fine, though at times, when I turn it off, it sometimes doesn't shut down and I have to use the power button on the back to turn it off. It works fine otherwise. I took it to the Apple Store. They ran it through it's paces and couldn't find anything wrong. I advertised on Craig's List for a price of 800$ but dropped it to 600$ for a young family trying to get a desktop computer for their first grader. I added a Mountain Lion upgrade, iWorks, and a childrens' typing software. I received the 600$ and gave them the computer yesterday. Today, I got an e-mail saying they were concerned about the hard drive, that it was noisy and they were worried about crashing. They were going to take it to Apple and have them look it over,and to see if there is a problem, whether it was the hard drive or the mother board. If it is the the hard drive, he said he might dicker with me and have me give him some of the 600$ back in order to replace the hard drive. I won't dispute the possibility of a problem, but I am the only user since day one, and it has been seldom used. I purchased it in the summer of 2010. While there is always the problem of someone trying to take advantage of an old guy, I think this is actually a young family with a precocious first grader with not much money. I would appreciate your thoughts about how you would respond if you were in my place.