Estimated Deflategate cost: $22.5 million

Well, here we are -- Day 500 of Deflategate.

The NFL, Tom Brady, the union and the Patriots have now spent more days arguing over the penalties associated with air pressure and subsequently the power of NFL commissioner Roger Goodell than the entire life of the ill-fated XFL (462 days). Should Brady get his way, odds are the battle will continue beyond the 2016 season, which means the total time spent on the case will be longer than the NFL career of Johnny Manziel (634 days).

To recap, we've had: a league investigation, a suspension of Brady, an appeal, a rejection of that appeal by Goodell, a lawsuit filed by the union, a district court judge ruling for Brady, an NFL appeal of that decision, a reversal of the district court decision by an appellate court and, most recently, a petition filed by Brady and the union to have all 13 judges in the court of appeals weigh in on the case.

So how much has Deflategate cost?

We asked three lawyers who have worked for leagues to sum up the costs, and the number we've arrived at is $22.5 million.

Estimated costs to the NFL: $14.7 million

The initial investigation by Ted Wells' firm, which was released May 6, 2015, cost the league at least $2.5 million, as Wells disclosed. The league also paid an outside law firm to originally come up with the case to suspend Brady and another one to argue the case in court. The NFL isn't paying hourly rates for law firms as deals are negotiated ahead of time, but the clock has been running long enough that estimated fees paid to these two firms have likely topped $6 million. Then, we have to calculate the time spent by the NFL's chief legal counsel Jeff Pash, who makes about $144,000 a week, based on his 2014 salary. Multiply that times the length of this case -- 72 weeks -- and an estimate that Pash has spent roughly 60 percent of his work time on this case, and that's another $6.2 million that has been racked up.

Estimated costs to the NFL Players Association: $7.1 million

The players' union has spent a good deal of money on the Brady case simply because it quickly became less about Brady and more about what the union characterizes as the overreaching power of Goodell, which the league argues was given to him by the union through the last collective bargaining agreement. Because the results of the case could affect all player discipline going forward, this is an important fight for the union to try to win. We know that, at last check in March 2015, the NFLPA was paying its main outside firm about $320,000 a month. Assuming the same rates, that gets us to $5.76 million over the 18 months of Deflategate. Assigning 80 percent of their work to Deflategate gets us to $4.6 million. Adding an additional firm for help with the case plus internal time devoted adds another $2.5 million.

Estimated cost to the Patriots: $750,000

The Patriots haven't done much in the legal realm, but they did hire an outside firm to write a 20,000-word rebuttal to Wells' report. That firm also wrote an amicus brief last week to support Brady's petition to hear his case in front of a full panel of judges.

The costs aren't expected to rise any time soon, as the NFL will have to respond to Brady's petition only if it appears as if the judges might hear the case. If Brady gets what he wants, odds are the case is heard after this season. The next big cost? If this somehow moves on to the Supreme Court.