My neighbor's "just fine" deck collapsed during a barbecue last summer. The inspector found dry rot in every single support post. The repair bill hit $22,000 because the whole structure had to be rebuilt to code. That's the real cost, it's never just the one visible problem. It's the hidden systemic failure you're agreeing to live with.
Oh man, that's the truth. "Just fine" is like a magic spell that makes your wallet lighter. My uncle said his roof was "just fine" until the attic looked like a water park. Then it was a whole new roof, new drywall, the works. That phrase costs more than most fancy vacations.