When we first started listing coins on GreedBay, I was advised that there is a danger with uncertified high-grade coins. Some buyers will open the flip, substitute a lower-grade coin, then return it and demand a refund because it was "not as described". I haven't yet listed any of the more valuable ones yet for this reason. Paying a grading service to certify them would be too expensive.
We put a note in each description that we will not accept a return if the cardboard flip has been opened. It's almost impossible to match the staple marks exactly, so I think I could spot it. However, I'm wondering if this is really a problem? Maybe unique to GreedBay? Have any of you more experienced sellers ever had this problem?