Me and some chums just survived on $30 food each for 4 days and we honestly ate like kings (although come to think of it, there were a few freebies, maybe it was more like $40 each). I imagine that if we had actually tried to purchase cheap things or just plain eat less (which is very possible) you could survive easily on $30 a week, especially if you reduced your weekly alcohol expenditure by $5-$10.