Thing to remember about anything cosmetic is that it needs maintenance
Veneers need replacing so once you're invested, you have to factor in the cost further down the line. At least, this was the case when I looked into it - this may well be different now, so will happily be put straight (no pun intended) if that's no longer the case
Botox? Needs topping up
Fillers? Same
Breast implants? Need replacing
Face lift? Surgical one Lasts 7-10 years. Non surgical much less.
Microblading? Needs topping up
So many women will take out loans to get breast implants, but less scrupulous clinics won't make it clear that they'll need replacing further down the line, and they'll need to think about the cost of further surgery in the future.
Botox and fillers are very very obviously not permanent, it's like getting your hair dyed.
But very few cosmetic procedures are actually 100% permanent - just worth thinking about maintenance when you start out.
If your teeth CAN be fixed with a brace then this will last, as long as a fixed wire is put in place. Depends what your issues are, as @stumblymonkeyagain says. I've had a couple of tiny chips in my bonding over the years, but cost a couple of hundred quid to get it patched up, so pretty low maintenance