There's a big ol' pile of toy Link PET Battle Chips on Ebay - 926 chips to be exact.
"These Battle Chips are for use with the Takara Rockman EXE "Link PET EX" handheld game system (not included). They can also be used on the Game Boy Advance "Beast Link Gate" accessory (not included). The Battle Chips themselves are predominately in mint, new condition. There may be a few with mild wear but for the most part the Chips are in exceptional collectors' shape and will definitely give your collection an enormous boost."
The auction is currently at $31, ending within a day or so. Complete details and more pictures available here.