Another standard sistutaiton -- all in or fold?

[Chu]

Sistuation 1
------------
I'm playing the $10K gaurentee over at PacificPoker, which I love because it is so easy to beat. In this tourney, the blinds move FAST. I'm in the BB with 55. The guy in front of me goes all in, which would cost me .5BB to call (easy call). Everyone folds to an above average player who raises it to 3BB, having 5BB left in reserve.

I was thinking, that if I was him I probably have an above average hand that want to go heads up vs. the all in player, but not strong enough to make this a multi-way. The right play here, given that assumption, is definatly all in or fold, since an all in from me, if he lost, would cripple him. My read on him is that it is 50/50 he will call or fold, and that he will probably fold any small pair. The question is -- is 55 a good enough hand to go for the all in?