Here's a better question. Someone walks up to you on the street. He takes your deck (so you know it's not rigged), he gives you 2 aces and takes 2 unknown cards for himself. He now lets you or someone you trust shuffle, and asks you the question. "Want to deal it out and winner gets 400k from the loser?"
If you're at a table though, you should always be able to financially afford losing everything you have in front of you. If you are playing at a table and you know you have the best hand, you have to call.
But this is an interesting question that I've wondered in watching deal or no deal. The optimally correct play can be determined using statistics, but is the decision that maximizes ev the correct one in the game? If you can have a sure 300k and are given a 50-50 at $1 million and a buck would you take it? Theoretically the 50-50 at a million has the higher ev but there's no way in hell you could convince me to take that. Give me the ****ing 300k right now.
In my example I'd say no. I'm sure someone richer would say yes, but I would be putting myself in about $395k of debt if I lost that, which wouldn't be the best way to be at this point in my life. Even if that's only 20% of the time, I'm not going to take that risk.