Single versus double cost variation
A single torsion spring on a standard door is a different job than a double door with two springs that let go at once, and a cracked panel on an older steel door usually costs more in labor than the part itself because those panels aren't a stock size anymore.\n\nMost of the houses we get called to here were built between 1949 and 1993, with the bulk from the 1960s and 70s, so a lot of what we're replacing is hardware nobody makes new anymore - which can mean sourcing a compatible part instead of a drop-in match.
