I bought my last three bikes on eBay and I think I got a good deal each time. It requires some time and effort.
But I watch a number of popular electronic items on eBay and I'm amazed at the prices people are willing to pay. For example, you can by a refurbished iPad2 (wi-fi 16GB) from Apple with the normal warranty (and free shipping) for $430. Yet people regularly pay $460-480 on eBay for used ones. WTF? They over-pay for new ones too. I don't get it.