I am confused. Is the OP looking for real casino chips from Vegas, or just any real casino chip set? The Vegas and Atlantic City gaming boards have laws that outline what a casino does with the chips when they close... They have no choice but to destroy them. So if you are looking for a set from one of those two places you are basically looking at getting either the Playboy chips from AC (pretty cool story there) or getting live chips for face value.
If you just want real casino chips like the one's in Vegas, check out the sales that thechiproom has from time to time. Other jurisdictions, like Washington, for example don't have the destroy law, and Jim from thechiproom is very good at getting his hands on them.
Jim got these chips last year, I bought most of them on the secondary market, and still need a few to fill out the set.
Or you can get home game Paulson chips like these on eBay. Paulson was purchased by GPI about 10 years ago and they are no longer available to non-casino customers.
Chips like these are rare on Craigslist, and when you find them they are gone pretty quickly. However, if you check CL and eBay enough you are bound to find a good buy or two. However, you have to sift through a lot, and I mean A LOT of junk to find the good stuff. However, many believe the fun is in the hunt.