Going back seems obvious, until you really think about it. Every little change you make would change who you ended up becoming and change the path you took, so almost nothing you remember about the last 15 years would be the same, and the resulting you would be different as well. All the people you met and the context you met them in would change as well, meaning some friendships you have now would no longer exist.

It's simpler for me. My kids were born after 2010. Chances are pretty slim my wife and I would be able to get the exact same egg and sperm to line up, meaning our kids would be different.

10 BTC would be fine for me.