Build one!
https://www.printables.com/model/152512-psx2usb-playstation-controller-to-usb-adapter
This topic has motivated me to - thanks for the inspiration.
Silly as it is, may add a topic about it over in creative works (prototyping a PCB for an atari 7800 controller before setting up a gerber to get good PCBs built as I did not want to pay silly amounts of money for the proline controller, blech). Been on a deep hardware kick lately, and this gives me an excuse to create another fun little toy.