Gio Gonzalez joins Stephen Strasburg and Jordan Zimmermann at the top of the Nationals’ rotation. (Ezra Shaw/GETTY IMAGES)

Billionaires tend to get the last word. Nice work on the Gio Gonzalez trade, and happy holidays to the Lerner family.

A 26-year-old all-star left-hander with statistics and power stuff comparable to recent playoff aces C.J. Wilson and David Price is a superb present for fans. The Washington Nationals now have a playoff-quality rotation — on paper.

Gonzalez is proven, in his prime, and under team control for the next four seasons. By 2013, will Stephen Strasburg (then able to pitch a full season), Jordan Zimmermann and Gonzalez be as dominant as any trio in baseball? Pitchers break — sometimes your heart. But it’s a sensible discussion.

The last two seasons combined, Gonzalez, Wilson and Price all had 31 wins with respective ERAs of 3.17, 3.14 and 3.12, plus nearly a strikeout-an-inning in a pair of 200-inning years. The others did it on winners. Gio did it with the Athletics, 14 games under .500. Gonzalez was on fire in September, 2.20 ERA, fanned 11 in his last start and has a southpaw curve as good as any.

Out of Gio, Jordan and “Jesus,” only Strasburg, the most gifted, could be called unproven. Last year, Gonzalez and Zimmermann were 10th in their respective leagues in ERA.

Best case: With good health, think Tim Hudson, Mark Mulder and Barry Zito from 2001 through ’04 in Oakland: 198-99. Worst case: Some blow out, everybody cries, the universal nightmare. But the Nats are now 100 percent in the fight. And, with their payroll not increased by the deal, which was made official on Friday — they got Gonzalez for four prospects — the Nats should not be finished this winter.

We may never know exactly what happened inside the Nationals in the days leading up to a mega-trade that, quite soon, may be seen as the moment D.C.’s franchise went from competence to contending. But we know plenty.

On Tuesday and Wednesday, the industry outside the D.C. area was buzzing: When are the Nats going to pull the trigger — on anything? It’s always like this with them. Why build a good farm system if, just once, you won’t do a prospects-for-star trade with a poor team? The Nats baseball people are “anguished and distraught” they can’t get a big deal approved.

This familiar pattern, with half the offseason already gone and a four-for-one trade (with a throw-in minor leaguer from Oakland) probably floundering, precipitated my column Thursday. When the Gonzalez deal was done the next day, I shook my head. And grinned.

Has Ted Lerner figured out how to laugh last? For 21 / 2 years, he said “no” to almost everything and paid a high price. All the losses in 2008 and ’09 changed his view. Does he now use the world around him as an indicator of when to act, like “blood in the streets” for stocks? If enough execs, scouts, stat folk, ex-star consultants, agents, media and fans reach for their pitchforks, does he say, “Time for a ‘value guy’ to act”? Or does he learn from his mistakes, but only when he’s reminded of them?

Maybe it doesn’t matter. Whatever the method, the Lerners have risked $126 million on one free agent, paid over slot in three straight drafts to stock their system, and risked four prospects for one all-star lefty.

Some will, very mistakenly, see this as a low-cost trade for which relatively little credit should be given to ownership with all praise reserved for those who drafted and developed the prospects, including a 41st-round pick (Brad Peacock) and a 10th-round pick (Tommy Milone), the kind of players who almost never have an iota of value.

However, if you think like an owner, you realize the Nats risked $50 million to $100 million in potential future value. They’ve given up legit kids that could eventually become three-fifths of the A’s rotation and their catcher. Likely not. Dealing for prospects is a long-odds game: out of many, a few. But any or all of Milone, Peacock, A.J. Cole and Derek Norris may make it.

For Oakland, the risk is nothing. In a division with the Rangers and Angels, the A’s need to rebuild after their 74-88 year. General Manager Billy Beane has traded his two best pitchers (also Trevor Cahill) for prospects. It’s pure poor-team “Moneyball.” How many years of quality MLB service will Beane get out of the ex-Nats at dirt-cheap prices (the first three seasons) to modest salaries (three arbitration-eligible years)?

The probability is that all of them together won’t have two years as good as Gonzalez just did, 15-9 and 16-12 with an adjusted ERA (in which 100 is considered average) of 129, which ranks above Price (122) and below Wilson (142 in the Rangers’ pitcher’s hell).

For the Nats, Gonzalez is far from cost-free. What they gave up is gifted cheap labor in quantity. Gonzalez might make “only” $20 million the next four years, unless he becomes a core long-term Nat with a big contract extension. But the Lerners know an injured Gonzalez and blossoming prospects in Oakland would be a huge net loss in value, if not in dollars.

Gonzalez led the American League in walks last year (91), always has done better in pitcher-friendly Oakland than on the road and threw 28 percent curveballs last year, which is a lot and can lead to elbow problems. All true. But he’s coming to the no-DH league, where starter ERAs usually drop by an average of 30 points. That should compensate for the Oakland effect.

For decades, this is the classic kids-for-a-young-star trade that winning teams, when they think they’re on the verge of a jump to the next level, have been making with poor small-market franchise that desperately need cheap respectability.

This is exactly the signal a team makes when it’s committed to winning soon. And, whenever the next shoe drops, it’s never the last big move.