Michael Bloomberg spent around 70 million US dollars (52 million euros) when he wanted to be re-elected as mayor of New York in 2005. His second term was considered a given, but he still paid. ”about 100 dollars per vote,” said Kees Brants, a professor of political communication at Leiden University.

http://www.nrc.nl/international/article2518799.ece/Dutch_politicians_campaign_on_a_shoestring