Candidates for CO governor are bankrolling their own races. Chances are, it won’t pay off.

Colorado’s 2018 governor’s race is shaping up to be a free-for-all.

But this contest isn’t really “free” for some of the candidates. Several are putting plenty of their own cash into the race, with eight months to go until the primary election.

Republican businessman Victor Mitchell has loaned his campaign more than $3 million already.

Millionaire U.S. Rep. Jared Polis, a Boulder Democrat, has put $630,000 into his campaign through Sept. 30.

And Treasurer Walker Stapleton, a Republican, seeded his war chest with $260,000, according to reports filed with the Secretary of State.

It’s a ton of money as a host of serious and not-so-serious candidates vie to replace term-limited Gov. John Hickenlooper. Hickenlooper spent nearly $5.4 million in 2014, while Republican Bob Beauprez spent $2.9 million.

Through September of this year, 11 gubernatorial candidates have raised and/or loaned their campaigns $7.5 million. Of that, 57 percent comes from the candidates themselves.

In Colorado, statewide candidates may receive maximum contributions from individual donors of $1,150 for both the primary and general elections. Candidates aren’t limited, however, in how much they spend on their own campaigns.

But a candidate’s money doesn’t always buy victory.

“It is becoming more and more prominent,” said Denise Roth Barber, managing director of the National Institute on Money in State Politics. “Yet we find that more often than not when somebody self-funds a predominant portion of their war chest, they don’t win. Because they haven’t gotten out and garnered support.”

Of the top 10 self-funded Colorado candidates from 2002 through 2014, three won their general elections, three lost in primaries, three lost in general elections and one candidate failed to make the primary.

Here’s a look at Colorado’s top 10 self-funded candidates since 2002:

No. 1: Polis spent nearly $6 million in his first run for Congress in 2008. Much of that went to defeating two other Democrats in a primary to see who would run to replace Mark Udall, who ran and won a U.S. Senate seat that year. Polis won the general election in 2008 and every election since.

No. 2: Joe Coors, the late beer baron, spent $3.5 million in 2012 to challenge U.S. Rep. Ed Perlmutter in the 7th Congressional District. Coors lost.

No. 3: Former Colorado State University athletic director Jack Graham spent nearly $1.9 million in the 2016 GOP primary for U.S. Senate. He finished second in the primary to Darryl Glenn, who lost to incumbent Democratic Sen. Michael Bennet.

No. 4: Joe Coors’ brother, Pete Coors, spent $1.2 million in 2004 running for an open U.S. Senate seat. The Republican won his primary election, but lost the Senate seat to Ken Salazar, a former Colorado attorney general who later served as U.S. Interior secretary.

No. 5: Republican Bob Beauprez spent more than $1 million in his second unsuccessful run for governor in 2014, losing to Democratic incumbent Hickenlooper.

No. 6: Businessman Marc Holtzman spent $835,000 trying to make the 2006 Republican gubernatorial primary ballot. He failed to gather enough signatures, giving Beauprez the nomination. Beauprez, a former Colorado GOP chairman and congressman, lost to Democrat Bill Ritter in November that year. (Beauprez spent $540,000 on his 2006 race, which puts him at No. 11 on this list.)

No. 7: Polis spent nearly $835,000 running for re-election to Congress in 2010. He won handily.

No. 8: Sen. Michael Bennet, a Democrat appointed by Hickenlooper to fill Salazar’s term, spent almost $804,000 of his own money in his first race in 2010. He defeated then-Weld County District Attorney and now-GOP U.S. Rep. Ken Buck.

No. 9: Colorado Springs Republican Robert Blaha spent nearly $774,000 in his effort to unseat GOP U.S. Rep. Doug Lamborn in 2012. Like others before and since, Blaha failed to defeat Lamborn in the primary.

No. 10: Wil Armstrong III, son of the former Republican U.S. senator, spent $550,000 in the 2008 6th Congressional District GOP primary. He lost to Mike Coffman, who has served in the seat ever since.