If you told someone a cure for cancer existed but there’s literally no way they could afford it, that sounds a lot like the cure effectively doesn’t exist for that person.

So I’ll posit that the weirdness of such a statement depends entirely on your audience.

If you’re one of the people likely to be able to afford such a cure, it might sound nonsensical.

I’ll also note that I intentionally selected a term with a more narrow definition “effective existence” vs a more general term “existence”. E.g. something can be true in general but effectively false in practice.