Mike's "very unusual for a casino to do that"
referred to the issuing of 5 different designs of $5.
For a small place it is unusual.
Before you worry about the effect on value of Mesquite Star chips, bear in mind a couple of things.
1. They were never valued that highly anyway.
2. The set includes the reserve rack $25 and $100 that were never released nor cataloged and before this time they were probably unknown to collectors. I would suggest there are few enough of those chips to warrant Mike's price for just those 2 chips alone.