This makes the bay area residents look cheap and unable to do basic math. If he really has $300M, even if he gave $1M he would still have $299M left, or in "G-math", $299.01M. With $299M he can probably buy all the other secret millionaires. It's obvious that G did it for the fame.
What about his appearance? He didn't look like someone down on his luck. He looked like someone going to his $500/month gym. It was a dead give away when he said he didn't know how to make coffee. This one episode significantly reduces the credibility of the whole show.
I hope Yahoo got their money's worth. Might be some zero's missing in the software he wrote.