150 Pesos (approx $40)/night
Coming off an exhausting 8-hour 4WD journey to an overnight train to a 3-hour border crossing to an all-day bus (including a late night breakdown and bus change), we were pretty beat upon our arrival to Salta. I'd say that's as good a reason as any to stay in a hotel (that's right, HOTEL) that was out of our budget.
It was actually a fair bit nicer than it appears in the photos. Free basic breakfast and (intermitent) WiFi. For what was meant to be one, but turned into three nights, we were livin high on the hog.