Who gets to run? Any swinging dick? Looks like a waste of money, to me...a waste of MY money.
Screw that. You wanna run for office? Go scrounge up your own money.
Some countries have non-partisan oversight. An agency who's job it is to ensure that elections are fair and that all parties follow the rules.
The rules include things like
maximum individual contributions.
maximum spending by any party
where voting stations are located, how many there are, who mans voting stations and how they are trained
what hours the voting stations open
what the rules are for early voting among other things.
In addition this agency determines where the borders are for voting districts (no gerry mandering by either party) and when they need to change due to population changes.
These rules are followed by all parties in all jurisdictions.
The idea is to make elections as fair as possible, ensure everyone who is allowed to vote, has a fair opportunity to vote.
No party can drastically outspend another party and the overall costs of elections to the parties, is contained.
In the U.S. often political parties are making up or changing the rules.
This Agency is the referee and they act on behalf of all voters to ensure a fair election. If a political party wants to win the election they have to do it through ideas and persuasion, not through rules they have put in place to gain a slight edge.
Who gets to run? Political parties pick their own candidates. Political parties collect money through contributions and fund raisers. They can use these funds for party functions like conventions, primaries or whatever. Often one political party may be richer than another. Richer donors, better fund-raising strategies, whatever.
The Agency can only control how much is spent during an election campaign, not how much an individual party spends on other things.
The way the U.S. Government works, I doubt such an agency could ever come into being. Voters might like the idea, parties would not.