Tiki...
First off, Welcome to ChipTalk! Be carefull, you may never leave!!
Your question is a very good one, as it has been asked and answered here previously, but instead of sending you off on an archice search, I'll try to answer here, albeit briefly.....
Atlantic City casinos are different that most other casinos around the World. New Jersey Gaming Laws/Regulations require that all casinos post a bond (or deposits) to a certain level so that if they ever go out of business or close willingly, the chips from that casino can always be turned in for face value.
So, Atlantic City chips will never drop below face value and to make certain that chips do not re-surface after being redeemed this way, Gaming requires monitored destructions.
So, surviving Atlantic City chips will always hold a certain minimum value (face value). For their value to increase beyond that, the demand needs to exceed the supply and for the lower denominations, that is unlikely, as the collectors have already snatched up many first quality Sands chips (when they were first released) and now many reasonable quality chips will be leaving the casino in droves.
Unless a Sands chip already has extreme value, it would be my guess that the current issue of chips from the Sands will not realize a significant value increase for the next 25 years! If any do, it will only be the higher value chips ($100 and up).
This is based on supply. If we look at demand, values can certainly go up if the collector arena esculates to the same levels as other collectible specialties.
I hope this answers your question and again, Welcome to ChipTalk.net!
Jim (Gaming Ore) Follis