Why the real estates are cheaper in the states?

I love watching the show "My First Home" on TLC on Saturdays and Sundays. It is fun to watch people hunting for their first home, going through the mortgage application process, and dealing with all the unexpected crises along the way. I plan to buy a house in the next one or two years. Watching the show is also very beneficial to me when I begin to start the house hunting.

However, I did notice something. It seems to me that the housing price in the States is so much cheaper than in Canada. For example, in Las Vegas, you can get a two bedroom detached house with garage for not more than $180,000. In Orlando, $260,000 for a four bedrooms house. In Texas, the price tag is even smaller. I don't think you can drop less than $300,000 for a detached house in any of the three big cities in Canada.

Why it is that way? I don't think those American cities have less population than Canadian ones. And the housing demand is probably also higher there? Maybe it is due to lower cost of the materials? But it should not be that significant, shouldn't it?

Or maybe I did not see the big picture. There are some places in the States with crazy housing price(Like NY?).