Help w/Late gameplay in 22's

[bluef0x]

I'm trying to improve my late-stage/bubble game and have been thinking of this one scenario that occurred today over and over again.

Party Poker No-Limit Hold'em Tourney, Big Blind is t150 (5 handed) http://216.119.70.224/converter/hhconverter.pl

UTG (t3180)
MP (t2220)
Hero (t1220)
SB (t910)
BB (t470)

Preflop: Hero is Button with 8[img]/images/graemlins/spade.gif[/img], A[img]/images/graemlins/heart.gif[/img].
UTG folds.
MP folds.
Hero is all-In [1220]
SB folds.
BB is all-In [320]


Now what is everyone's thoughts on what to do here?

My reasoning was that BB was going to call with almost any two (turns out he thought about it for a long time before deciding to call, so there is always the chance that they fold.) and ace-8 is a favorite vs. two random cards. But should I have played it more safe to gurantee an ITM finish? I'm kind of split on what to do and would like some input from other people...