Managed to snag a Playstation 4 development kit on buyee a few weeks ago. (with OG PS4 for comparison) : r/PS4
動作未確認 PlayStation 開発機 development kit devkit prototype2 prot(PS4本体)|売買されたオークション情報、ヤフオク! の商品情報をアーカイブ公開 - オークファン(aucfan.com)
Sony PS4 dev kit FCC filing shows off extra ports, 2.75GHz max clock frequency | Sony, Ps4, Kit
PS4 Developer Kits spotted | eTeknix
Finally got what I consider to be a grail in my collection, a PS4 Development Kit. : r/gamecollecting
Don't worry, it's just a devkit: New concept renders of the Sony PlayStation 5 - NotebookCheck.net News
PlayStation 5 devkit and final next-gen console designs are revolutionary in comparison to previous efforts leaving high expectations for the PS6 - NotebookCheck.net News