Why do so many expats care how much another expat spent to build his house?
So many different variables including location, builder, material quality, design, square meters, fencing, etc.
Just because another foreigner built a house for cost A, is no guarantee you will even get close.
My father has been a builder for 50 years.
You can build houses very cheap in Thailand, however, when you are a foreigner and have to hire a Thai builder, no way you are going to get the best deal.
It might be a good price for you as a foreigner but it could have been much cheaper.
That is the reality!