Late stage blunder with A Js??

[mdntokr]

Ok, I was wondering what you guys think about my call in this situation. I'm not able to get the hand history, so I'm going to have to recount it for you.

I'm playing in a $15 10k guaranteed tournament on Pacific Poker. There's 20 people left and I'm currently in 5th place with a stack of 45k. There's a player 4 spots to my right who I watched go all in preflop about 5 times in the last 15 hands. The one hand in which I got to see his cards, he had A 7 suited and made this play one off the button when everyone had folded to him (at this time he had a medium stack and the BB had a bigger stack than he did).

So here's the hand. There are 2 folds to this player and he pushes all in with about 34k. I hold A Js and it's folded to me. There's three stacks that are a little smaller than me behind me and the blinds are 2k/4k. What would you do with a stack of 45k in 5th place? I know in this situation you usually need a much stronger hand than A J to call, but I have to figure he'd make this move with any pocket pair, A 6 and up, K Q, K J . . . and probably some hands that are even worse. Is it worth here to try and almost double up and move into 2nd with a commanding chip lead at my table?

Regardless, I decided the answer was yes and wound up losing to 5 5. I feel like I made the right decision in that situation (not knowing what he was holding of course). But I'd really like some feedback on this play.