The Courthouse News Service has this article about the oral argument in the Eleventh Circuit in Cowen v Raffensperger, the Georgia lawsuit over the 5% petition for U.S. House candidates who are not members of a party that polled 20% of the vote in the last election for president in the entire U.S., or 20% for Governor of Georgia.
The article says the attorney for the Secretary of State said sometimes it costs millions of dollars for a Democrat or a Republican to win a primary for U.S. House, and therefore it is seemly that a petition drive for an independent or minor party candidate might also be very expensive. But half the time, major party U.S. House primaries in Georgia only have one (or zero) candidates on the ballot.
In 2018, out of the 14 districts, there were no Republicans on the primary ballot in the 5th district, and there was only one Republican on the ballot in districts one, two, four, six, eight, nine, eleven, and fourteen. In the 2018 Democratic primaries, there was no Democrat on the ballot in the eighth district, and there was only one Democrat on in the second, fifth, eleventh, thirteenth, and fourteenth districts.
In 2020, there was only one Republican on the ballot in districts three, four, five, ten, eleven, and twelve. There was only one Democrat on the ballot in districts two, three, six, eight, eleven, and fourteen.
So, for those two election years, out of 56 primaries, in 27 of them the winner could have won by spending zero money.