When would you fold AA's

[formula72]

Lets Assume

Your in the world's largest card room offering no-limit tables ranging from 25-50 NL to 1 Billion 2 Billion NL.

You have $1,000 and sit down at the 25-50 NL with the minimum buy-in.

You are dealt AA's on the very first hand and your opponent pushes you all in with KK's for you to luckily double up.

You must take you $2,000 to the 50-100 NL where the same thing always will occur.

Assuming at some point you will go busto at what point will decided to not risk it and cash out assuming you start with $1,000.