What changes the price
Step count, open sides, returns, baluster resets, subfloor condition, material choice, stair width, and landing details can all change the final scope.
Materials-only versus installed
Online stair parts can look cheaper because they usually exclude demolition, prep, fitting, cleanup, warranty, and the labor required to make the staircase look finished.
Why a written estimate matters
A good estimate explains what is included, what is not included, how complexity is handled, and what the homeowner should expect before work starts.
Next step
Send FIR a few photos of the rooms or staircase, your city, step count or square footage, and the material direction you like. The estimate can then explain material, labor, prep, stairs, trims, transitions, delivery, and timeline in one clear scope.