This is perhaps the most confusing advice ever.
You can find many knives under $40 that should last you many many years, however a lifetime of actual use? Probably not.
OP: I will say this as an ex collector/user of swords which can be applied to knives.
If you find a antique in good condition, the simply truth is: It was not used. Usually for good reasons: Flaws, not functional, etc. It's a rare occasion when an antique is in good condition, and functional.
If you find a battered antique in terrible condition: chances are it was a great tool for someone and may have some great history but unfortunately is probably no longer safe to use.
So asking for a knife to last you a lifetime means you will need to baby the knife. Actually using it for a lifetime means you will likely retire it WELL before your lifetime.