Where did you buy?
Unless you have a big downpayment, $500k basically means a pretty big mortgage, young families don't always have that kind of money. A significant number of these townhouses aren't sold to young couples, they're sold to investors with foreign money hoping to flip a $500k townhouse (I don't think there are many $500k units) for $700k and a $700k one for $900k.
You know why you had to look so long for a place? It's not supply, it's the increased demand from speculators, foreign investors and real estate agents starting ridiculous bidding wars.