In 75208 the prices do range from $336k http://bit.ly/12yOT0U to $1M http://bit.ly/YFaRQs
You can see a map of these currently available in 75208 at http://bit.ly/10JdD6y
Prices do vary within a zipcode. This 3 to 1 ratio is not uncommon.
To answer mesutter's question, Yes, it is a stunner on Argonne.
As I said, a 2BR, 1 1/2 BA for $1.5M must be a real stunner. The original question was "What is the average sale price for 2 br / 1.5 ba". Argonne doesn't meet either my or Josie's criteria. It's only $1.0M, and has 4BR and 3 1/2 baths. So just where is that 2 br / 1.5 ba $1.5M property?