most places in the U.S. the biggest cost of building a home is labor not the parts to build it with

 Of course there are always exceptions to this truism like where land is incredibly expensive or places where the pieces of lumber or items to put your roof on or items to furnish your home with might be more expensive.

But, generally speaking if your land isn't going to break the bank in cost it is better almost to build your own home than to have to get a mortgage to buy your home. 

However, you do have to be young enough or be retired to pull this off.

For example, if you are retired you might build your own home while you live in a mobile home or motor home or trailer if it is legal to do that where you are building your own home. 

My father and I built his retirement home starting when I was 20 years old until he retired in 1980 when I was 32 years old. I wasn't always there because I was married from the time I was 26 on. But, he would work in San Diego most of this time until Friday he would get off work and then my mother and he would drive Friday night almost every weekend out to the desert above Yucca Valley up Old Woman Springs road to where he owned his 2 1/2 acres. When we started to build he had to have water hauled to a gravity feed 1200 gallon water tank and before that we got a septic tank installed and poured our foundation. For pouring the foundation we got many friends to help the weekend we did this after my Dad and I dug the footings ourselves for the concrete Slab which is much more common in California for Ranch style home that are one level without a basement. However, you have to have your septic tank and below floor plumbing in before you can pour your cement slab.

So, I have built a home with my father and he and I also built a home in Mt. Shasta as well.