2756
Generally, a stair lift can be installed professionally for about $3500 for a standard lift, on a straight set of stairs and only a single flight. Turns and non-standard stair configuration will increase the price substantially.
a ladder or a flight of stair
Flight of stairs and Fleet of ships.
4 feet
12-17
A flight of stairs in it's entirety is a staircase
stair and stare
Stares and stairs or Stare and stair
A hand truck with a stair climber built in.
It is one word "staircase" (open flight of stairs, usually with rails).
Please clarify what exactly you want to calculate.