It soon could cost more to run for mayor of Minneapolis than governor, U.S. senator or state legislator.

On Wednesday, the city charter commission will vote on a proposal to raise the fees to appear on the ballot from $20 to $500, the first increase in nearly 50 years.

The proposal, aimed at discouraging frivolous candidates, is already prompting concerns that such a dramatic increase will discourage people from running.

“I think it’s excessive and I think it dampens the spirit of an open democracy,” said mayoral candidate Mark Andrew, a former Hennepin County commissioner who now manages an environmental firm.

The move follows the city’s 2009 adoption of ranked choice voting, in which primaries are no longer held to narrow the field of candidates. Instead, citizens pick their top three choices, allowing for an instant runoff. Candidates must garner at least half the votes to win election.

This year, at least seven candidates are competing to replace Mayor R.T. Rybak, and more are likely to jump in before the Aug. 13 filing deadline.

The charter commission will also vote on raising fees to run for City Council and Park Board from $20 to $250 and $50, respectively. If approved, the measure would then go to the City Council, where it would require a unanimous vote.

Council Member Cam Gordon, who was behind the proposal, said he’s heard anecdotal stories of people filing to run for fun or to promote their career, and “the $20 amount seems to be affordable to do that … the sense was that if the bar was a little bit higher, then people have to think about it more seriously.”

The proposed increase to run for mayor would make the fees higher than those for U.S. senator ($400); governor, judge and state attorney general ($300), and state legislator ($100).

But the proposed fee isn’t the most expensive one out there. In San Francisco, one of the few major cities to also have ranked choice voting, filing fees for the last mayor’s race in 2011 were $5,058. Candidates collected thousands of signatures to avoid paying.

In Minnesota, candidates can opt out of paying the fee if they gather enough signatures of support. That would be the lesser of two numbers: either 500 signatures or 5 percent of the total number of votes cast in the town, ward or other election district at the last general election when that office was on the ballot (which would be 2,298 for a Minneapolis mayoral candidate this year).

So in the mayor’s race, a candidate would need to gather just 500 signatures. The requirement would be much less for a council campaign, and Gordon, whose seat is up for grabs along with the rest of the 13-member council, said he might go that route.

While fees are needed to cover administrative costs of elections, an increase could deter people from running for office, said Jeremy Schroeder, executive director of Minnesota Common Cause.

“If it’s just to keep frivolous people from running, I would want to make sure this is the best way to do it. … We support getting as many people involved in the democratic process as possible,” he said.