Usually (not too sure about AC, though), those chips never were intended for play or included in the casino's inventory; and most likely the item comes directly from the manufacturer or agent for the manufacturer to be used in a presntation or as a gift of some type.

There's a $10,000 plaque embedded in Epoxy from Casino d'Montreal here in Florida that I've been trying to get my hands on for over 15 years, now. It was presented to a well-known day boat casino operator who passed it on to his sister. She lets me hold it every time I pop in.