How much is too much political spending?

I was watching Face the Nation yesterday and amazed at how much money is being spent on this election. Here’s part of the show transcript:

“BOB SCHIEFFER: Today on FACE THE NATION, it’s all about the money, or is it? Whatever it’s about, the midterm election will be the most expensive ever. How expensive–3.7 billion.

That’s billion with a B. With nine days to go, both sides have their big guns on the stump.”

$3.7 billion. No tally yet on the cost of the North Dakota races. Do you think it’s necessary for elections to cost this much?