A few places in the USA are expensive, California, Pacific Northwest, Florida, Northeast, however the rest of the country is pretty cheap. American houses are like 2-3 times the size of British ones on average. The vast majority are detached or semi-detached.
To give an example cities as diverse as Detroit, Pittsburgh, Cleveland, St Louis, Kansas City, Houston, Dallas/Fort Worth, Atlanta. Have mean house prices around the 75,000 to 100,000 British Pound Mark. Many other cities like Minneapolis, Denver, Minneapolis, Chicago, Phoenix, Tucson have house prices around 100,000 to 150,000 pounds on average.
Australia on the other hand has big houses on large lots like in the USA but the prices are high all over the place. Where I live the mean house price is around 100,000 British Pounds and that is considered cheap. The mean house price in Sydney and Perth are over 200,000 pounds on average for example.