Ask HN: When,if ever, is a “flight tested” booster more valuable than “untested”

Not my field, I just thought it was an interesting question. Obviously mechanical systems have fatigue, stress, wear and tear. But new they can have undetected manufacturing faults, or assembly errors.

Given that stress and fatigue are generally well understood, at some point, will insurance on a new rocket cost more than insurance on a used rocket? And will SpaceX start charging more to use one of their "flight tested" boosters?