The gers are standardized. There is a big daily market in Ulaanbaatar where you can get all spare parts and complete gers. In 2017, the price for one ger was something like $1000.

For that money, you get a well-isolated easily movable tiny house in a country where you are allowed to settle everywhere (but if you have 2000 sheep with you, you should better discuss the usage of the pastureland with the locals) without paying rent (outside the city).

Choosing a ger for housing is not only about tradition and culture. It is quite rational in that situation.