A straightforward cable swap on an extension-spring door - release tension, pull the old cable, route and clamp the new one, reset the drum - is usually the bulk of the visit. Where it runs longer is when the cable broke because the pulley or bottom bracket wore out first, which we see more often on doors that match Center Point's median build year of 1977 than on recently replaced systems.
One honest limit: if the track itself has bent from the door dropping unevenly, that's a separate repair, and we'll quote it separately rather than bundle a guess into the cable price. Median household income here runs around $92,500, and most owners we talk to want the real number before we start, not after.