[Decathect]

It's an arms race. The ideal position is a. spend as little as possible and b. outspend your opponent. This inevitably results in spiraling escalation that harms both parties. The obvious solution that the US has avoided and France has embraced(1) is enforceable limits on spending. Like many applications of the prisoner's dilemma, the existence of external authority limiting the freedom of participants actually results in a better outcome for everyone involved.

1. This is the entirety of what I know about French campaign finance as of five minutes ago: http://www.loc.gov/law/help/campaign-finance/france.php