No, niacin isn't expensive; but YOU said to Infarouge "if you're too [LAZY] to go to a sauna..."
I, myself, have enjoyed FIR (Far-Infrared-Sauna) saunas in the past. I cannot go any longer because they are simply too expensive in my area, either for appointments, or to purchase one for my home.
I'm certainly not too LAZY to go to one, so I felt a need to defend the poster you answered (Infarouge).
That is what I was addressing; I'm sorry you got confused.