We don't have a fixed number to publish for roller replacement here, since the honest price depends on how many rollers are shot, whether brackets need replacing too, and how much the track has drifted after decades of use. What we can tell you is what drives the number: nylon rollers run cheaper in materials than the labor to true up a track that's out of line, and a full 8-to-10-roller set costs less per roller than doing two or three at a time and coming back later. Given the median income in this pocket of the service area, we don't see many owners trying to stretch a patch job - most decide to replace the full set once we're already there with the door open. We'll give you the actual figure on-site once we've seen the door, not before.