I also put less than U$S500. Similar to guillegee and the bookcellar, I rent a room in a Ph, eat at home, don't really shop for clothes or go to clubs/bars very much, always take public transportation, etc etc. Mainly hang out at other friends' houses or house parties. Luckily there is a lot of free cultural stuff in the city to do. It's a big change from how my life was in the US, but I'm still happy.