We don't have a set price to quote you in writing here, because off-track jobs range from a five-minute roller swap to a full track and bracket replacement, and the honest number depends on what we find. What we can tell you is that the newer, lighter track common on 2003-built Brentwood homes is generally cheaper to replace than the heavier gauge track on older houses closer to Livermore, since the parts themselves cost less.
We quote on site before we start any repair beyond the initial diagnosis, so you're not guessing. If a cable or spring failure caused the door to come off track, we'll price that repair alongside the track work rather than sending a second call out for it.