For some strange reason I like to keep track of prices on some Nikon goods on Ebay. The only thing I can say is Ebay is the worst place to buy Nikon gear.
About six year ago prices on Ebay were either fair or fabulous deals, but with the advent of online photography communities and online reviews of older lenses, and with every Tom, Dick, and Harry, and every Jane, Mary, and Barb thinking they could be professional photographers because they don't have to spend money on film (and mistakes), prices went up, and up, and up, and up. The past few years prices have gone to astronomical sums for certain lenses--namely the very fast zoom lenses and the Noct Nikkors.
A few years ago one could easily find a 20-35 for about $300-450US--lately that lens has been hovering in the $750-1200US range. You'd think people would realize that it's an older lens, and repairs and spare parts are becoming harder to find. For the same price (actually somewhere in between that price range) you can pick up the newer 17-35, which is slightly sharper and a bit wider, and is about the same size.
Another lens that's suffered from this strange phenomenon I like to call mass-internet hypnosis is the 80-200 f/2.8 D (the two ring version). This is an old lens that has been replaced by the AF-S, and the VRI and VRII lenses. A few years ago that lens was going for $500-750 for ones that were in excellent shape. I've seen used ones on Ebay go in the range of $750-1000US! What a rip-off! You can still buy them new for $1200, and those come with a 5 year Nikon warranty. But if you're going to spend that kind of money it makes better sense to buy an AF-S or a used VRI/VRII.
What's driving prices up so high on older lenses--there are two thoughts in my mind: 1) the look-at-me generation (aka generation Facebook) has more money to spend or 2) mass-internet hypnosis has taken over the market.
I tend to lean more toward my mass-internet hypnosis thought--what do I mean by that? We used to call it the "herd mentality". So why did I change its name? Because the internet has ton's of reviews out there that claim the 80-200 f/2.8D is a bargain buy compared to the newer lenses. Say what? Yup, you heard me right. Just search for reviews on it online. People will believe just about anything without really researching it themselves. What basically happens is tons of people believe these reviews (which seldom compare lenses side-by-side) and drive prices up. Heck, I've seen AF-S lenses in amazing shape sell for the current Ebay price of the D version of the 80-200 lens.
It's like the stock markets--people drive prices up (or down) based on things they read on the internet (news of war, or rumors of war, or natural disasters), rather than doing research on what a company can actually deliver over the long term. If we follow my line of thinking the opposite can happen when a lens is rated "poorly" (even though it may actually be a gem). If someone were to write a bad review about a certain lens, well, what do you think will happen to the price? Oh! Wait--that's already happened with some older lenses that no one remembers were actually "bargain" lenses of their day.
My advice is get accessories on ebay but stick to online retailers and brick and mortar stores to buy your lenses--Ebay's days for finding great deals are sadly numbered (if they're aren't already over).
While I understand that many photogs overseas have no other option, other than Ebay, this post is mainly aimed at my North American readers. We have plenty of options over here ranging from retail stores, garage sales, estate sales, and even places like fredmiranda.com, where, for the most part, people know the real value of a lens and don't sell junk to unsuspecting customers.
It's buyer beware out there.
Till my next rambling, or post, or review, this is, hey, hey