I don't remember when I bought PS3, but I know it wasn't about 6 months or so from release. Couldn't tell you when I bought PS4, though.
The original fat PS3 died on me, like with everyone else since they didn't do something with the motherboard where it was heat resistant and it would burn itself out.
They're throwing around crazy prices for what the PS5 could be and you don't want to buy a lemon. It'll have shit launch titles anyway, same with PS4.