ebay, seriously. For medium rare items with no collectors value it is a sellers market - there is no other place where you can find as many users with a irrational lust for some piece of equipment, and the determination to spend too much on a potentially broken item.
Specialised auction houses are better for ultra rare stuff where only a small segment of the potential buyers would pay full price for the collectors value. And forums like this here are better for more commonplace items, whose price depends on condition rather than availability, and where the level of trust in the community controls how much you can surcharge for the condition of the merchandise (on ebay everything sold privately is broken by definition and priced accordingly).
