I see condition as a bigger factor than rarity.
I have seen chips with a high end book value of say $30 sell for twice that price on ebay, because they are in "uncir" condition.
Pick any high end book value, $50, $100, $200 and if the chip is really in uncirculated condition it seems the selling price is always at least and usually more than the high book price.

Just my observation on Ebay.

Scott