Good example of being confidently wrong. You are thinking of the little Basic interpreter that was on the pack-in consumer demo disc. Not the Linux Kit which was a very real initiative and had universities involved. We were using them in a big dedicated lab.
Not at all, you're mixing up with YA BASIC, that came with PS 2 demo disc.
People that weren't there keep mixing channels on this one.
To acquire PS2 Linux, you had to pay additionally 300 euros for the Linux distribution, the PS2 hard disk, and cables that would only work in monitors using sync on green signal.
Initially the price was much higher, and got reduced to around 300 in 2004.
Turns out most open consoles are full of either crapware or emulators, which is the reason Sony and Microsoft eventually gave up on some openess.