In reply to T.enClimb: We spent 3 months in Patagonia a couple of years ago, travelling from Santiago to Ushuaia and climbing in several places for a few weeks at a time, including Bariloche and El Chalten. Our budget was canadian$30/day each (2 of us travelling), I'll let you do the maths.
We were close to or under this, camping most of the time and hostels maybe 25-30% of the time. Only very occasional meals out. The main expense was busses so if you're planning on staying in one place it will be cheaper. IRIC the campsite in El Chalten was roughly $5/night/pp. You can leave things there when you're off in the hills for no charge, though you do have to take your tent down. Food in El Chalten is expensive and relatively limited (and needs a visit to at least 5 different shops to get what you need!).
Bus costs vary massively based on which service you want. We hitched a bit which was fine.
The park entry fee for Torres del Paine is expensive, maybe $50ish? Climbing there is a total hassle too, many expensive permits are required which are hard to get. That's one reason why El Chalten is more popular - no permits, no entry fee and easier access.