Here are my takes on values in chip guides:

* Not every author sees every chip sold (or for sale)

* Some chips trade very seldom and sales price depends on how bad the buyer wants it, not necessarily what several buyers think it's worth.

* New supplies of older chips come onto the market all the time and reduce the value of older chips. Guides won't reflect this till the next update.

* Some guide values represent what the author thinks the chip should sell for, not necessarily what it has sold for. Examples are the modern reproductions and fantasy chips that TCR thinks are worthless, but which we collectors sometimes pay a significant amount for.

* Until there is active, daily trading, like the New York Stock (Chip) Exchange, there will always be differences of opinion on value.

* One guide may list what the author sold the chip for (retail price) and another may list what the author bought the chip for (retail price). Difference may be 2:1 or even 3:1 to one due to dealer markup. Auction prices versus chip-show prices also provide different numbers for the same chip.