The build cost is equally cheaper.
Where i buy my components which is not nearly as cheap as many other country's i come up with a 1,91Kh/s per $ for for a nVidia setup where as i get 2,1kh/s per $ for a AMD setup (all expenses included). heat = more space required or heavier cooling, these cards also run a lot colder than what AMD does as well as reports are that cards barely get upto 65 degree, and heat is something that is very hard on AMD as they easily run upto 90+++ unless you have a ton of fans and space between the cards.