well but with 99% of PS4 games working on PS5 and PS+ being a thing it could be worth it to provide an ultra cheap option that's in impulse buy territory to get people locked into their ecosystem. Even if it only results in PS5 sales years later it's still worth it for them. Those cheap buyers are then more likely to get a PS5 when it is cheaper.
That's a viable strategy. Personally, I don't know to what extent people are locked into the ecosystem. I had a 360 (I also had a PS3 but I only had a few games for it and it broke) but that really didn't factor into my decision to buy a PS4, because if I wanted to play the older games I still had the hardware. It may be a little different if there's something like PSPlus where the games are tied to an account, but I still don't know.
Really comes down to how many of those late gen adopters they think will remain with the brand and how many of them could be persuaded to buy a PS5 instead.