If I were a time traveler, I wouldn't care less about half of your wealth, or a thousand times your wealth, or wealth in general.
What is paper compared to time travel?
Further,
Power corrupts, and absolute power corrupts absolutely. Power is an opportunity to facilitate and harvest evil. The more power, the greater opportunity for evil to flourish.
Time travel is POWERFUL.
This is why I think time travel should only be used for things that are positive, beneficial, and not for trite affairs or particularly selfish interests. If you're not actually helping a situation or persons, if you are not governing yourself as per rights and responsibility, then it presents a general inherent risk, and is probably not worth the bother. If you are not doing something righteous with it, then the opportunity for evil is too great to justify the endeavor.