I guess it depends on how badly you want the chips in question. If you want them so bad that you will pay a high premium over what the expected value of the chips are them someone will more than likely sell. Unless it is a set that only 1 or 2 people own. That could take a lot more money.
Now if you want them, but only at a price you feel they are worth, that is a different story and you may never find them then.
Good luck with the hunt though!