Assuming it's in 100's, that's fifty bills. Is the wallet really an option?

Checked baggage is not a very good idea either. Well to be blunt, it's a really horrible idea.

I would vote for the carry on or laptop case, if you can secure it in one of those by locking a zipper or something and don't let it out of your sight.

Another option may be to split it up, some in your pocket, some in the carry on, etc.