https://www.rocketleague.com/news/rocket-pass-launches-on-september-5/. Not so scummy as first thought. 10 keys for the premium track, can earn 6 back if you get all the way to level 70 on it (devs say about 168 hours to do that), can earn all 10 back if you go beyond level 70. So free if you play enough. Rip my free time :(.
I am kind surprised no one has made a Pi to cart adapter for older systems... Like a universal flash cart just use a Pi Zero and SD card and off to the races