There is no answer to this question. It depends on the supply and demand for the individual chip.

For example ... there are supposedly thousands of the last two issues of the Sands $1 chips, the blue and the orange. This is more than enough supply for every chip collector to have one if not a few of these chips. Yet the prices of these chips defy the economics of supply and demand and continue to bring in prices from $10 to $20 a piece and beyond. I doubt that another box of these chips would have any effect on the price of this chip, except perhaps upwards with the additional publicity.

Take another example ... say there is a chip where there are only one or two surviving examples from a well known Vegas casino. The chips would be worth quite a lot, perhaps $5,000 to $10,000. The effect of a newly found box of these chips would be dramatic. If supply now outstriped demand, the price would come way down.

So there is no answer to your question, it depends on the chip.