Well, you do have to remember that the collectors that the dealer sells to are using the same price guides. And, if the collector buys a chip based on an "old" guide and the newer guide, when it comes out, shows a higher value, it is the collector who benefited in the long run, not the dealer.

Of course prices don't always go up in the chip collecting hobby. New "finds" of chips frequently drastically reduce the market value of older, once-rare chips. So, whether you're buying or selling, I guess it's a crap-shoot.