wtf am I doing wrong?

[roxtar]

I've busted out no less than 4 spots from the money in the last 3 tourneys I've played in (one 12th, two 9ths). The trouble I'm having is when to start stealing blinds. The tourneys I play don't have that aggressive a blind structure so I find that the starting levels are fine for someone looking to play TAG, but they only start you off with T700 so unless you double up in the 1st hour or two you can find yourself with 4x BB pretty quick. At what point should I begin to worry about stealing blinds? I know how to steal blinds and the basic concept behind it as far as position etc. but the timing is the part I'm having trouble with. How many BB do I get down to before it begins to become necessary for survival?
I've cashed in these touneys before but when I have it's been complaetely card related, just wonderful runs of pocket pairs and dumb opponents. I think I'd rather bust out first than bust out on the bubble.
Any help would be appreciated.