The seller lingjr_dot_com has 3 Playstation development tools for sale. I’ve seen some of these in the past but they’re usually very expensive.
SONY DTL-H2000C 1010 1080 PS Controller – x3 @ $39.99 ea.
PS2 Branded Keyboard (i think these were the same keyboards bundled with the Linux kit for ps2)
You’ll probably find more of his stuff intriguing so check it his other listings.
Seller snickel8 has a few signed items: