No. The article's numbers are based on median value not average value, so your example isn't relevant. To get the published median value to work in your example, townhome prices would indeed have to fall a bit. The shocking statistic that I'd observe in your example is that sales of houses greater than a million dollars fell by 50% in one month.
You are correct:
"Median" is not the same as "Mean" nor the same as "Mode".
From my (admittedly simple) example, the "median" price of all houses sold in August was $100,000 and the "median" price of all houses sold in September was $105,000.
And the "mode" for all houses sold in August was $100,000 while the "mode" for all houses sold in September was $105,000.
Given the assumptions I presented, neither of these last two statistics is very useful, IMHO.
Nevertheless...
Let's look at two months of assumed sales data in which each house (in an admittedly small sample) has a different selling price to see what can happen to the "Median", in spite of price inflation, if fewer "expensive homes" are sold in "Month 2" than "Month 1".
You are correct:
"Median" is not the same as "Mean" nor the same as "Mode".
From my (admittedly simple) example, the "median" price of all houses sold in August was $100,000 and the "median" price of all houses sold in September was $105,000.
And the "mode" for all houses sold in August was $100,000 while the "mode" for all houses sold in September was $105,000.
Given the assumptions I presented, neither of these last two statistics is very useful, IMHO.
Nevertheless...
Let's look at two months of assumed sales data in which each house (in an admittedly small sample) has a different selling price to see what can happen to the "Median", in spite of price inflation, if fewer "expensive homes" are sold in "Month 2" than "Month 1".