Here’s a quote I found on NPR that I think pretty much sums up everything:

“By Election Day, $2.4 billion will have been spent on presidential campaigns in the two-year election cycle that began in January 2007, and an additional $2.9 billion will have been spent on 435 House and 35 Senate contests. This $5.3 billion is a billion less than Americans will spend this year on potato chips.” - George Will