I currently own an Olympus EM-D but I am thinking of picking up a used GH2 for video. As Panasonic shooters, GH2 specifically, are there any pitfalls I should look out for when purchasing a used model? Also, are there any questions I should ask the seller before agreeing to make the purchase? Also, one last question, what price range would you consider to be fair for a used GH2? I have looked at Adorama and B&H for their prices but since I may be going down the route of a private seller I figure it would be fair to offer a little less than what they offer. Thanks!