Normally, stairway $5.00 per step, floor $5.00 per sqaure yard. As the carpeter itself depening the quality you like. Also, for the floor footage, you need add roughly 10% extra as you need to cut and through some carpeter. 8 r8 L8 h8 @$ a1 Z+ M! B# k- A9 ~# i3 U! T
This is just rough idea.