NicolasD,
Great - you got some good deals - but the those arent common. Let me ask you...would you be willing to sell all those items for what you paid ? How about what you paid plus 15% ? Plus 30% ? Plus 50% ? I am guessing not, which proves the fact that your prices arent "values," only great deals you hunted down and had patience for. It also seems your knowledge level on these items is high and therefore were able to purchase items below market value because you had knowledge others didnt have. Good for you, bad for the seller...thats what I love about Capitalism. If one can add value ( or find value ) where others cant, you win.
I can show you examples where people paid much more for those same items you bought...so, what I do is the throw out the highest and lowest prices and focus on the middle prices and average them...
Also, if you have seen my other prices guides, you will see that I usually write the following disclaimer:
Prices are the approximate amount one should expect to pay for a XXX lens in excellent, but used, condition. Glass and body should be clean and without scratches or marks. Hoods, boxes, caps and finer condition will all add to price. XXX lenses can and do vary widely in price depending on exact condition, serial # and pedigree. Pricing was gathered from sales on photo.net, ebay auctions, Tamarkin auctions, the LUG, and camera dealers. Prices biased towards ebay auctions and private sales on photo.net. Expect to pay more directly from a dealer.