That has to be for commercial real estate, or you've been ripped off. There is no possibility of a single family dwelling ever having plumbing problems of that scale.

But maintenance costs are in general a landlord lie. They wouldn't rent out their properties if costs where anywhere near income. As for my own anecdote, my landlord has spent at most 0,5% of what he's gotten in rent from me on maintenance over the years. A normal tenant won't break anything or induce any maintenance costs.