Yes Anna, for market comparison price per square foot is only one tool in the toolbox.
The factors you mentioned, Condition, "Location, age of home, amenities and comps within 1/2 mile of similar homes" are more important than a ppsf average.
But Joeroy asked the question because he is
"Trying to get info for home insurance comparisons, thanks"
For that purpose knowing the PPSF for a narrowed size range (say 1400 to 1700 square feet) No fixers, no condos no land, no converted garages. Getting a targeted ppsf for something comparable to the home he wants to insure does make sense. He just did not give enough info for it. Perhaps his insurance agent asked him to get this answer?
And guess what? I just ran the Targeted search on sold houses (last six months using the narrowed criteria. My result was almost identical to Mary's answer and Norm Roberts answer. Even though I eliminated fixers, smaller and bigger houses.
Average: $125 per square foot on a list of 68 sold homes that fit the narrower criteria.