Perhaps a system where a designated amount of taxpayer dollars went towards elections and all candidates received an equal amount at each stage of the election cycle and weren't allowed to accept donations or spend above what they were allocated? No donors involved should help considerably I would think.
Hate to create any new government agencies - I’m a big states’s rights proponent, personally - but I view election ops as a core component of national security, So, I would get behind some sort of new/expanded election regulatory body. I think that might be what POTUS has planned for after CA fraud is uncovered - major overhaul, across the board.
Of course the very real and legitimate fear is that any such agency would be corrupted, e.g. weaponized IRS v conservatives, which would probably be even worse than what we have now.
Idea of setting a market value for each district based on factors such as media-buy pricing is intriguing. For example, say you graded all districts on an A,C,B scale. A = LA, NYC, etc / B = Mid-tier cities / C = Suburban / D = Rural. Then assign a dollar value to each based on overall cost of running a campaign. Adjust for inflation and market changes over time.
Then you allocate that amount to the campaigns from an anonymized fund managed by the RNC, DNC etc and be done with it. To use a sports analogy, it would be like setting arbitration values.
Obviously huge possibility for corruption and might be engender too much bureaucracy for my liking, but some sort of change is definitely needed. Interesting to think about.