Chips from my personal collection that fit into the Hard To Find to Rare category.
I honestly don't know how many of each exist so someone may chime in say oh no, there are X number of one of them.

My general knowledge, which again might not be 100% correct:

Claridge was a backup chip never put in play but used in some tournaments and a few leaked out, perhaps as tips for drinks.
Bally's Park Place is in mint condition, not sure if it was ever put in play?
Tropicana is in mint condition, not sure if it was ever put in play?
Trump Castle was a Prototype and is in mint condition, never put in play.
Trump Plaza is in mint condition, not sure if it was ever put in play?

I have complete sets of the 3 tournament chips from Bally's, Tropicana and Trump Plaza.

Scott