A proper investigation of issues in housing requires a look beyond the price. As I mentioned, price can be indicative of an issue, but is not the source or cause of the issue. In the same way your sore throat may be caused by a sinus infection, if you fail to look for the root cause you may treat the condition inappropriately.
Home Price Calculations
The recent GF Herald article about housing prices brings to the forefront an issue with housing price calculations. The Herald used index numbers based on sales, which is problematic. What was the composition of sales in a given month? If there were only high value homes there could be sample issues. Also, when you attempt to make a comparison between two areas you have a double issue with the inconsistency of samples.