Owners call with a used unit in the garage: “I already bought one on Facebook. Can you just install it for $795?” That sounds like free margin because the rail and chair invoices left the bid. They did not leave the trip, the template, the set hours, or the chance that the rail is an indoor kit on an outdoor stair.
Open the free stair lift bid calculatorA contractor-supplied straight indoor rail still carries the rail and chair invoices. An owner-supplied unit that actually fits zeros those lines and keeps the same set hours. On a typical cheap special — $42 wage, 30% burden, 15% overhead, 20% target margin, eight miles — the contractor-supplied bid is about $5,333. Zeroing a $2,200 rail and a $650 chair drops it to about $1,236, but the owner-supplied walk-away stays about $989. Taking the Facebook special to “just install what they bought” at $795 still loses about $194.
| You supply | They supply, it fits | They supply, wrong rail | |
|---|---|---|---|
| Rail and chair invoices in the bid | Yes | No | No |
| Set hours | Same | Same | Same, plus an inspect trip |
| Walk-away on the cheap special | About $4,267 | About $989 | About $1,422 |
| At $795 install-only | Loses | Still loses | Loses more |
Used listings skip the template. Rails come up short, indoor kits show up on porch stairs, and the box is missing brackets or a charge point. Setting the wrong unit means a second dispatch plus hardware they expect you to eat. Price that callback on the same stair before you agree. The calculator adds a starting inspect trip and a missing-hardware kit on top of the rates you already typed.
Open the stair lift bid calculator, enter the stair you are standing on, and put their install-only number in “price you’re considering.” The who-supplies table scores that number against you-supply, owner-supplies-it-fits, and owner-supplies-wrong-rail. Nothing is uploaded.
This is the same arithmetic as how much to charge to install a stair lift. Hospital discharge this week is a different decision — see should I expedite a stair lift for hospital discharge. It is not a building-code determination, an accessibility approval, a medical-device prescription, or a reason to refuse a customer — it is the walk-away number on each supply path.
Only after you price the set without the rail and chair invoices. Templating their used rail is still a trip and crew hours. A $795 install-only special often sits under that walk-away number even when the lift is free to you.
Usually not. Zeroing a $2,200 rail and a $650 chair drops the bid, but loaded labor, attach hardware, travel, and overhead stay. On a typical straight indoor rail the owner-supplied walk-away is still above $795. A rail that is too short or missing brackets adds a second trip.
That is a second dispatch plus missing brackets or a charge point they did not have. Price that callback on the same stair before you agree to install whatever they rolled into the driveway. The calculator adds a starting inspect trip and missing-hardware kit on top of your current rates.