The amount of wealth that this time traveller can generate is dependent entirely on how much high value knowledge he can sell to everyone in the past, which is why i'm assuming you chose to send him to 2000AD rather than 1492. The answer is also dependent on what you define as wealth.
What prosperity is, where growth comes from, why markets work http://democracyjournal.org/magazine/31/capitalism-redefined/
Everyone else seems to have answered your specific question pretty well, so I won't go much further with it. But if you want to make this a broader question, and bring him back to other points in history as well, you can explore some really great questions.
As many of these other answers have explained, the wealth he could earn is very dependent on the context of the society he arrives in.
The fact that any "new" (stolen from the future) ideas he generates would be protected by the american system of copyright law isn't guaranteed if he ends up in some earlier society and immediately gets robbed or simply is forced to recall new inventions under duress from, say, King <PERSON> of England.
And This lack of structure still happens in most of the world
Why Capitalism succeeds in the west and fails everywhere else by <PERSON>
http://www.columbia.edu/itc/sipa/S6800/courseworks/spirit_capitalism_samuelson.pdf
And that doesn't even begin to deal with what would happen if this time traveler was part of an unacceptable social group in the wrong time and place.
As others have said, his samsung phone and USB stick are only as valuable as the insights engineers in the past might gain from them. 207
Without USB ports, or the technology to make them, or the software to interpret files saved on the USB, that 128 GB of storage might as well be 1Kb, or 0kb. Without a phone charger, electrical grid, or any knowledge of how to manufacture such a device, the phone becomes, at best, a general guide to what might eventually be manufacturable in the future.
Even then, the collective intelligence of whichever decade he arrives in will dictate how much his knowledge is worth. He might be head of engineering at samsung and he still wouldn't know everything about how to design, manufacture, and maintain a smartphone from scratch. 284