Bryce Harper won’t be a free agent for three more years, but that hasn’t stopped people from writing about his next contract. Over the last few months, David Schoenfeld and Jeff Passan have discussed his eventual price tag recently, and Harper himself vaguely addressed the topic in a radio interview yesterday:

Harper was asked during an interview with 106.7 The Fan’s Grant Paulsen and Danny Rouhier whether he has thought about the possible magnitude of his next contract. “I was talking to an executive this offseason,” Paulsen said. “At one point in time they said you could be the first $400 million player. Do you ever think about your future and what’s possible, in terms of you could break records for the money you make at one point in time?” “Yeah, I mean I don’t really think about that stuff. I just try to play the years out and do everything I can to help my team win,” Harper said. “But don’t sell me short. That’s what you’re doing right now to me, so don’t do that.”

The idea that $400 million is selling Harper might seem ridiculous, but he’s right; as long as he continues to perform near expectations, the winning bid should be substantially higher than that.

The $400 million figure essentially comes from two factors; the Giancarlo Stanton extension — which guarantees the Marlins slugger $325 million over 13 years — and our human affinity for round numbers. Everyone agrees that Harper is worth more than Stanton, and since he was the first one to crack $300 million, the easy suggestion is that Harper will be the first to crack $400 million, since it’s the next round number on the scale. But that’s not a particularly scientific way to figure out what Harper’s market value might look like — especially since Stanton’s contract was an extension while he was two years away from free agency, so it doesn’t represent the free market’s valuation of him as a player either — so let’s try some other approaches instead.

We first need to acknowledge that Harper is not historically unique.

Harper vs A-Rod, Through Age-22 Name PA AVG OBP SLG wRC+ Off Def WAR Alex Rodriguez 2271 0.313 0.364 0.543 130 101 34 20.8 Bryce Harper 2143 0.289 0.384 0.517 147 125 -7 19.4

Through the same point of his career, Harper’s numbers are very similar to Alex Rodriguez; he hits a bit better than A-Rod did at the same point, but he doesn’t play shortstop, so those differences mostly offset. And Rodriguez gives us a data point on what the market will pay for an inner-circle Hall of Fame talent hitting free agency in his mid-20s.

After the 2000 season, the Rangers gave Rodriguez a 10 year, $252 million contract. At the time, the average salary for a Major League player was a little over $2 million, as total league payrolls in 2001 added up to $1.9 billion; the AAV of Rodriguez’s deal was essentially 12 times the league average. The average salary this past year was just over $4 million, so calculating for inflation, the AAV of A-Rod’s deal in present value is roughly $48 million per year, so it would have been the equivalent of him signing for 10/$480M this winter. And that’s in 2015 dollars; Bryce Harper will be a free agent after the 2018 season, and with three more years of inflation, prices should only be expected to rise.

Now, we shouldn’t just assume that Harper is going to get the A-Rod deal. Rodriguez reached free agency a year sooner, so he was selling his age-25 and beyond seasons, while Harper will be selling his age-26 and beyond years. Rodriguez was a shortstop, so it was easier to argue that his defensive value would hold up even with an eventual position switch, while Harper’s status as a corner outfielder means he’ll essentially have to be carried by his bat when injuries begin to take their toll on his fielding. And, fairly or not, the Rodriguez contract is widely considered a mistake, as Texas ended up paying a significant portion of Rodriguez’s deal when they traded him to New York; it is going to be difficult to sell an owner on a contract value by saying “this is the A-Rod deal for the current era.”

But you don’t need the A-Rod deal to make a case for spending $500 million on Bryce Harper; you can simply look at what the same money would buy in free agency if you spread the wealth. I did this exercise with Mike Trout a few years ago, showing that a team would be better off with Trout and some random low-priced outfielder than the two best free agent outfielders on the market that winter; Jacoby Ellsbury and Shin-Soo Choo. When the market has decided that declining +3 WAR players are worth $20 million per year, it’s not too hard to illustrate why a +7 WAR player heading into his age-26 season would be worth well north of $40 million per year.

But just for fun, let’s use some current examples. The two best young free agent hitters on the market this year were Jason Heyward and Justin Upton. Heyward got $23 million per year for eight years, while Upton got $22 million per year for six years, so their combined AAV is $45 million per season. Upton and Heyward project to be worth about +8 WAR next year, though a good chunk of that is based on Heyward’s defensive value. Harper, by himself, projects at about +7 WAR, and with more certainty about his value, since it’s based on performance we can measure more easily. The market value of a superstar slugger expected to consolidate roughly the same value into one roster spot should not be significantly lower than dividing the same money into two players who add up to the same total value.

In today’s dollars, the market suggests that Harper’s performance is worth something like $50 million per year. Now, he’s probably not likely to reach that AAV on the kind of term he’s expected to ask for, as there are inherent risks with signing up for so many years well into the future, and the big value of going with multiple lesser players is that you don’t have to sign up for as many years. Harper isn’t going to settle for a 6-8 year deal, so he’ll have to take an AAV discount in order to get the 12-15 year deal that will result in a huge total contract valuation. But the question isn’t whether or not he’s going to break $40 million a year, but how close to $50 million a year he can get on a long-term deal.

If he settled on the A-Rod length contract, however, and only asked for 10 years, I’d think he’d have a shot at getting $50 million a year. Assuming Andrew Friedman and his crew and are still running the Dodgers in 2018, it’s not too hard to see them pushing for a high salary/shorter term offer like this, given their resources and desire to spend on youth rather than decline. But if Harper wants to maximize the total dollars in his contract, he’s probably going to point to Stanton’s 13 year deal and argue that, as a better player and a better bet to stay healthy long-term, he deserves 14 or 15 years. He’d have to take a significant discount on the AAV to get that number, but if the goal was just to maximize the total contract figure, 15 years at $37M or $38M per year would get him up to $550 million.

And while these numbers sound nuts, we have to keep in mind that players that are this good are not that difficult to project going forward. Harper is one of just eight players in baseball history to post a career wRC+ between 145-155 through his age-22 season; the other seven are Albert Pujols, Eddie Collins, Eddie Matthews, Tris Speaker, Mickey Mantle, Mel Ott, and Rogers Hornsby. That’s six hall-of-famers and a guy that’s a slam-dunk selection when he’s eligible; guys who hit like this at this age just don’t stop playing well unless they get hurt.

Injury risk, or some kind of off-field issue derailing his career, is really the primary downside here. With Harper, you don’t have to wonder too much about how good he’s going to be, as guys with this level of talent remain elite players until their bodies break down. Assuming he has three more high-level seasons heading into free agency, $500 million is a perfectly reasonable ask, and depending on how well baseball’s economy does in the next three years, $600 million isn’t even out of the question.

Of course, with opt-outs becoming all the rage, it’s possible that he’ll pioneer an entirely new type of contract with player options every couple of years in order to give himself maximum leverage. But if he decides that the goal is to just get as a large a total contract as he can, $500 to $550 million is probably going to be the reasonable bidding range, and if someone wants to defer a bunch of the contract, I could see a team deciding to push $600 million.

It’s going to be the bidding war of the century. $400 million won’t even get you to the table. As Harper himself said, don’t sell him short.