Appropriate AQo aggression, not first to enter?

[AZnuts]

Party SNG $20+2. BB50 level. I haven't been involved much at all; the one read I have is MP2 has limped several times now.

converter

UTG (t740)
UTG+1 (t915)
MP1 (t1045)
MP2 (t1370)
Hero (t730)
Button (t470)
SB (t680)
BB (t2050)

Preflop: Hero is CO with A[img]/images/graemlins/diamond.gif[/img], Q[img]/images/graemlins/spade.gif[/img].
<font color="#666666">3 folds</font>, MP2 calls t50, <font color="#CC3333">Hero raises to t200</font>, Button is all in T470,<font color="#666666">3 folds</font>, <font color="red">Hero calls 270 more.</font>

I was hoping to get heads up against MP2 whose limp looks very weak, but after the button pushed his smaller stack, I felt obligated to call with the 2.7:1 pot odds. (but I'd rather have AK now)