You are attempting to reconcile facts with fiction. For those with unlimited time, it a fun exercise and very entertaining.
The reality is, real estate data found on Trulia and Zillow is FICTION.
They do not apply responsible control in defining a comparable.
They do not apply responsible control on location.
The do not apply responsible control on time.
The data is not current.
Suitable for entertainment only
No one should expect anything but random numbers from such sources.
But, you already knew that.
Yet, here you are.
If you want real numbers, you need access to a source of reliable data.
You won't find reliable data on the book shelves labeled FICTION and attempting to reconcile the two will result in looking for Gate 9 3/4.