Betting on facts - Showing confidence

Everyone is very focused on Romney's offer of a $10,000 bet. I'm wondering why if he was so certain that he was right he didn't offer Rick Perry odds at (let's say) 2 to 1 up to $10,000. It probably still wouldn't be that good a move politically, but making someone put their money where their mouth is better done a way that doesn't emphasize how that person has lot less money when one is running for office in a country with a significant unemployment problem. Either he did actually lose control and wanted to assert dominance or he forgot that his peers in this presidential race aren't going to act like his peers in the business world. Someone worth $2.8 million should be able to afford a $10,000 bet if they are confident enough about their facts, but Rick Perry either knew he was wrong or knew that this was an opportunity to outmaneuver Romney politically.