San Marino's median household income runs $187,633, well above the $94,792 median across the wider service area we cover from Pasadena. That number matters more than it sounds like it should, because it changes the repair-or-replace math. On a house where the owner's time is worth more than a Saturday spent watching torsion-spring tutorials, a $40 roller kit from a home center often gets touched by someone who has no business near a wound spring, and a trip to urgent care costs more than the service call would have. We're fine with owners handling small stuff: lubricating hinges, tightening loose bolts on the track, swapping a remote battery. Springs, cables, and anything under tension is not a DIY job at any income level - the failure mode is a broken hand or worse, not a redo. If your door is original to a house built in 1943, the hardware on it is old enough that guessing wrong about what's safe to touch yourself is a real risk, not a hypothetical one.