http://www.bbc.co.uk/news/world-us-canada-11570633 Former eBay CEO Meg Whitman, the republican candidate for the governor of California, is running the most expensive non-presidential campaign in history. She has spent about $140 million (though most of the money is her own). For comparison, the entire Australian federal election in August cost just $52 million. In the UK, the maximum a political party can spend on a national election is $31 million. Perhaps some regulations on campaign spending are needed...
While I feel that "buying votes" shouldn't be able to occur in a democracy, I don't feel that regulations would solve the fundamental problem that most voters do not know much about the people whom they vote for.