[cheekygeek]

Most people have long realized that the "average price" that is quoted for lenses in the Lens Review section are misleading. This is the nature of averages. As my grandpappy just to say, stick your head in a fire and your feet in the freezer and "on average" you'll feel just fine. Averages that include prices paid for new lenses (back in the day) being averaged with the thrift store price that somebody else paid isn't going to give you a good average. Worse, the system discourages many reviewers from honestly stating the price that they paid, since they don't want to look like "chumps" for paying more than that "average". (Notice how many reviewers don't state a price paid?)

Even worse is the "Price History" section. It is so bad that I would rather have it turned off completely than provide the misleading information that it does. Let's take just one example: SMC Pentax 67 / SMC Pentax-6x7 165mm F2.8 Reviews - 67 Telephoto Primes - Pentax Lens Reviews & Lens Database
The graph would have you believe that in nearly two years the price of this lens has been under $150. In fact, if you look on that infernal auction site we all know and avoid this particular lens has sold 8 times in the last 30 days and only twice has it gone for as little as $145. Three times it has brought over $300 and twice over $340. If you took the average of what it has been selling for in the last 30 days (on that U.S. auction site ) you would get a figure of $250 (roughly double what the Price History graph would lead you to believe).

An accurate Price History graph would be useful (if it got its data from actual sales reporting in Marketplace by buyers and/or sellers, for example) and not just from the self-reporting in the Reviews section.

I have the feeling that the programming that went into providing that nice little Price History graph was probably a lot of trouble to implement, and it sure looks good. If only it provided data from a more realistic source.

[Adam]

I have the feeling that the programming that went into providing that nice little Price History graph was probably a lot of trouble to implement, and it sure looks good. If only it provided data from a more realistic source.

Actually I used the google chart API, which is really easy to use

The goal will be to eventually have an ebay-style listing system where users select the items they're selling in the marketplace via a dropdown. Technically we do have a lot of pricing data as it is right now, but it would be a ton of work to standardize it...

[riff]

Worse, the system discourages many reviewers from honestly stating the price that they paid, since they don't want to look like "chumps" for paying more than that "average"

I think another factor is at play here too. One buys lens for x and commits that to public record now one wants to sell for 2x which may still be a good price.

Is it possible and practical or even a good idea to mine the info from ebay completed listing?

[Adam]

Yup, and our own completed listings, for that matter. I'll try to throw something together that will at least allow us to start collecting data.

Adam
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[riff]

Sizzle, that's hot! Rust never sleeps and so it seems, neither do you.

[cheekygeek]

Actually I used the google chart API, which is really easy to use

But the data the chart uses is the reported pricing in the Lens Review contributions, correct? And it throws out any unreporteds?

[SteveM]

There is another aspect that makes the trending data inaccurate and that's location. I can't think of any way to account for that within our price listing other than providing an average overall for all sales.

The reason that I bring it up as it's a substantial indicator in price. For example, I browse through eekbay for listings that only ship to the USA, and close to the end of the listing, I send a polite email to the seller asking them if they would consider shipping to me just a little ways up from Seattle. The answer is usually yes, and I can then bid on the item. This seems to save me anywhere from 40% to 70% of the cost as compared to listing normally open to me.

I don't think we are seeing the same trending on our marketplace but I'm sure it causes a wide fluctuation in the perception of price.

[Adam]

Well, the marketplace does have location data, so that can technically be accounted for. If you look at the number of sold threads, there are tens of thousands of data points there....