I don't really see any reason that you need to go broke here. This is how I look at the situation...

It's the start of a high stakes buy-in tournament, and you have to assume your opponents are competant until they prove otherwise. You open raise, and he comes on top of you with a lot of players still to act.

Because of this, and because the blinds are very low compared to the stack sizes, you have to know he has a real hand. AA/KK are probably the most likely. To be realistic, we can throw AK and JJ in this category too. These hands likely call your raise though this early in the tournament.

This is how I'd handle this situation.. call preflop. Look to hit the set.. ideally on a Q high flop. When the flop comes down J84, you have to know there is a good chance you are behind. AA/KK/JJ all have you dominated, and AK certainly isn't going to pay you off if you bet hard into him.

I check here and if he fires out a respectable bet, I'd let him have it. Against a very agressive player maybe you can go for a check-raise or bet out, but I don't see the point of going the distance here out of position when you are likely dominated and losing your stack if you are behind, and winning a modest pot if you are ahead. JMHO..