Markey - I just checked and the age of listings currently available in the "Whittier" neighborhood range from 1880 to 2007 - I will come back to that in a second - logic says average price per square foot would be a very helpful indicator on the home buying process - however, my experience is that it is less helpful than it might seem.
Why do I say that? An example may be helpful. I recently had a listing in the suburbs sell and it sold for $120/sq ft - a home close by but on a different street from my listing has the exact same floor plan, same age, same size, same builder and is currently available (and was available to the Buyer that purchased my listing) - the list price on the home still available generates a price per square foot of $87/sq ft - so, why would the Buyer purchase a home at $120/sq ft when a home just down the street with the same floor plan and size was available for only $87/sq ft? Typically the answer is in location, condition, and finishes - in my example, my listing had nicer finishes (more hardwood, more tile, newer and better carpeting, solid surface countertops, etc) and had a much better location with views. So, the finishes, condition, and location can make a fairly large difference in the price per square foot.
In a neighborhood like Whittier, where the age of the homes can vary significantly, and therefore the:
2) modernization (heating, electrical, plumbing, roof, windows, insulation, etc),
3) type of basement (none, cellar, crawl space, stand up, etc),
4) parking (garage, no garage, on street, off street, garage falling down, etc),
5) size of yard,
6) location (busy street, quiet street, adjacent buildings, etc),
7) finishes (countertops, flooring, light fixtures, bath fixtures, etc)
can also vary tremendously, the price per square foot becomes less meaningful because all of the items I just listed have a significant bearing on the price a Buyer might pay for a home but do not factor in the calculation of "price per square foot". In the older neighborhoods of Denver, I have seen Buyers pay significantly more on a price per square foot basis than the lowest price per square foot, or even the average price per square foot because the location, condition, and finishes provided the best value to the Buyer.
So, the "average price per square foot" could be for the entire neighborhood, or it could be for the homes that are similar in construction, location, finishes, age, parking, etc - my experience is that those numbers could be very different, especially for a neighborhood like Whittier that is undergoing a transition and you just want to be careful in how you use the number. Best of luck in your search.