Ushuaia [1] has abundant accommodations, but it’s long been an expensive destination in what was, until recently, an expensive country. Demand is high, though, in the summer months of January and February, when prices rise and reservations are advisable. One heartening development is the proliferation of nicely priced backpacker hostels and several bed-and-breakfasts—known by the semi-English acronym ByB.
Links:
[1] http://www.moon.com/destinations/chile/southern-patagonia/ushuaia-argentina