Trump/Republicans spent a total of $2.13 billion vs. $3.37 billion by Harris/Dems. This is inclusive of "dark money".
[1] https://www.opensecrets.org/2024-presidential-race/donald-tr...
[2] https://www.opensecrets.org/2024-presidential-race/donald-tr...
[3] https://www.campaignnow.com/blog/dems-outspent-gop-2-to-1
[4] https://www.brennancenter.org/our-work/research-reports/dark...
[5] https://www.pbs.org/newshour/live-update/election-news-2024/...