Quarterback Josh Rosen at his introductory press conference on Friday.

Steve Keim is not averse to paying a premium for quarterbacks, as the Cardinals' general manager gladly opened the check book for veteran Carson Palmer until he retired and then chased Kirk Cousins in free agency this offseason.

Even so, Keim has always dreamed of nabbing a talented signal-caller in the draft because of the considerable upside it offers.

Not only can a young arm keep a team competitive for years on end, the first half-decade of his career comes at a considerable discount. The rookie contract scale keeps the salaries of young players well below market value. Every impact rookie is a bargain, but none more so than quarterbacks, the most valuable position on the field.

On Thursday, Keim got his man, moving up five spots to select UCLA quarterback Josh Rosen with the No. 10 overall pick. Over the next four seasons, Rosen will cost an average of $4.4 million per year on the salary cap. Compare that to Cousins, the crown jewel of the free agent class, who will receive $28 million per year over the next three from the Vikings.

Cousins has proven himself on the NFL level, and Minnesota was so close to the Super Bowl last year that the move made sense. But it can be argued the Cardinals are actually better off by falling short in the Cousins sweepstakes because of the financial flexibility that results if Rosen pans out.

"What do you mean 'if' he does?" Keim deadpanned, before acknowledging the high-risk, high-reward nature of the choice. "If he doesn't, I might not be here."

There were five quarterbacks taken in the first round, and history insists not all of them will live up to that billing. The ones that don't will force their teams back to the drawing board. The ones that do will set their franchises on a promising trajectory.

The recent past is a good example. The Eagles moved up to the No. 2 spot in the 2016 draft to take Carson Wentz. He is a budding star and figures to have the team in contention for the foreseeable future. But even when Wentz went down with a torn ACL last year, the ripple effect of his bargain contract paid off.

[READ: BRADFORD'S TEXT TO ROSEN]

The Eagles were able to secure a top-flight backup in Nick Foles with the extra money, as well as assemble a deep and talented roster. Foles was named Super Bowl MVP after leading the Eagles to a 41-33 win over the Patriots and was buoyed by an excellent offensive line, running game and defense.

The Seahawks used this formula to win a Super Bowl when Russell Wilson was on his rookie contract, while the Rams are currently making their push as Jared Goff enters his third season.

The Cardinals have some key players – running back David Johnson, defensive end Markus Golden and linebacker Deone Bucannon among them – on expiring contracts, and if Rosen is the starting quarterback in 2019, the team will be in great cap shape to make any moves it considers prudent.

"It is everything," Keim said of a quarterback on a rookie deal. "We have talked about it over and over, that it is a big pizza pie and there are only so many slices to go around. There are a number of NFL teams that have shown the ability to spend money in other areas" because of the rookie quarterback's presence.

[READ: THE FIFTH-YEAR OPTION AND JOSH ROSEN]

The gravy train won't last forever, as a fifth-year option increases the salary – albeit still at a discount – and a market-value extension would then beckon.

"Eventually, if he is good enough, you are going to have to pay the piper," Keim said.

That's a good problem to have, and one that won't need to be resolved for a half-decade. Meanwhile, the Cardinals are getting a motivated Rosen, who thought he should have been taken within the first three picks of the draft. The pairing has through-the-roof potential.

"I want to win Super Bowls for the Arizona Cardinals," Rosen said. "I think over time that will work. That will happen."

With an affordable rookie contract in tow, there is no better time than now.