Here's some details, which explain it. I think they are nothing but junk chips, marketed to be collectibles for the gullible. (but the baseball collectors probably think I'm silly for collecting "casino junk")

New from The Topps Vault: Official Topps First Edition Collector Chips featuring the 2004 World Series Champion Boston Red Sox! This exclusive eBay promotion will feature 250 graded collector chips, 10 of each of the 25 unique chips from the set. The complete set consists of 24 World Champion Boston Red Sox players, including Curt Schilling, Pedro Martinez, Manny Ramirez, and David Ortiz. Also included is a special chip of Manager Terry Francona. The 10 chips being offered are sequentially numbered; each is the first of ten off the production line for each of the 25 players. Each custom chip is professionally graded by PSA and weighs 9 grams and measures 1.5 inches in diameter.