Playboy chips are not rare, I'm sure every chipper who wants one can get one without much trouble. At any given time there are always several up for auciton on Ebay. For a common $1 chip, they are valuable because there is so much demand for them. By no means are they rare or should they be advertised as such.

The Harrah's Reno PMSC $1 chip is another example of a common chip (you can still pick them up for face value off the craps tables) but is valued by collectors who are willing to pay $5 to $10 for one.

On the other hand, there are probably thousands of chips of which there are no more than a handful that survive, but are not very valuable because of lack of demand. These are chips that are from the "wrong" location, they have the "wrong" mold and are not very attractive.