IF ROY HALLADAY ends up being worth the money for which he signs, then any debate over the prospects who have changed hands will be rendered moot.

Because if Halladay earns his $20 million-plus per season through 2012 (and, if there are options, perhaps beyond), then the Phillies will have one of the top three starting pitchers in the game for the next 4 years.

They will have an absolute horse, one who has thrown at least 220 innings in each of last four seasons while posting an ERA of under 3.75 in the most challenging division in baseball.

They will have a guy who has thrown 25 complete games over the last three seasons, a guy who is 4-2 with a 2.79 ERA in six career starts on 3 days' rest, a guy who has appeared 26 times as a reliever, a guy who is 18-6 with a 2.84 ERA in 37 career appearances against the Yankees.

And, most importantly, they will have him during their much-discussed "window of opportunity," giving him two full seasons with Ryan Howard, Chase Utley, Raul Ibanez, Shane Victorino, Carlos Ruiz, Placido Polanco, Cole Hamels, Brad Lidge, Ryan Madson and, provided the Phillies exercise his option after 2010, Jimmy Rollins.

Couldn't the Phillies have held on to Cliff Lee and then attempted to sign Halladay after the season as a free agent, saving top prospects Kyle Drabek and Michael Taylor?

Probably not. Because all indications were that Toronto was going to trade Halladay. And whoever landed him likely was going to sign him to a contract extension, which would have removed him from the market.

Why not just sign Lee to a contract extension?

I'm sure the Phillies asked themselves the same thing. Which is why they met with Lee's agent at the winter meetings. But Lee's camp has sent plenty of public signals that suggested they were looking for a monster deal.

And who would you rather pay $20 million a year to?

Halladay is 15 months older than Lee, but he also has 11 full big-league seasons under his belt and has posted an ERA of under 3.75 in eight of his last nine. Lee has been one of the top pitchers in the game for the last 2 years. But he has a long way to go before he proves himself to be in a class with Halladay.

Keep in mind, Lee allowed six or more earned runs in six or fewer innings in three of his 12 starts with the Phillies. Halladay has had one such start in the last two seasons, and just five in his last five seasons.

How risky is paying monster cash to a pitcher through his 36th birthday?

Glad you asked . . .

Halladay's staying power

Roy Halladay will turn 33 in May. A 3-year extension would bring him through his 36th birthday. Now, attempting to project the future health of players is an impossible task.

Halladay has an extensive injury history, but very little of it has to do with his arm. Since 2004, when he went to the disabled list twice with shoulder fatigue, Halladay has missed time due to a pulled groin, an appendectomy and a broken leg that occurred when Kevin Mench hit him with a line drive. But aside from that 2004 season, which Halladay said was caused by training too hard in the offseason, he has had no arm problems.

Halladay compares a lot more favorably statistically with other pitchers who finished their 32nd year of life as some of the most dominant in the game.

While 32 might sound old, consider: Roger Clemens turned 32 in his second-to-last year with the Red Sox. Curt Schilling turned 32 when he was still a member of the Phillies. Schilling, Clemens, Greg Maddux, Randy Johnson and Kevin Brown were just as dominant or more dominant between the ages of 33-36 as they were between 28-32. Exceptions? Jason Schmidt, Pedro Martinez and Bartolo Colon. But Schmidt didn't have the track record that Halladay has. And Martinez' slight build may have contributed to his breakdown. Halladay is 6-5, 225 pounds.

So, is he worth it?

Assuming the reported names are accurate, what it boils down to is this: Anybody who labels anybody other than Seattle the winner in this whole thing is fooling themselves.

Even if Halladay pitches up to his billing, this deal could still easily be a push when all is said and done 3 or 4 years from now: I'd expect Michael Taylor to get strong consideration for the Opening Day roster. Drabek still needs to work on his changeup - lefties killed him at Double A last year - but could be ready to get a shot at the Blue Jays' rotation late next season. And Travis D'Arnaud has tremendous upside, although projecting catchers is always tricky business.

Seattle, on the other hand, now has Cliff Lee to go with Felix Hernandez, which could easily prove to be a better 1-2 punch than Halladay-Hamels.

From a monetary standpoint, Halladay is clearly worth a 3-year, $60 million extension.

* John Lackey signed a 5-year deal with the Red Sox that will take him through his 35th birthday, averaging $16 million to $17.5 million a season.

* CC Sabathia's 7-year Yankees contract will take him through his 34th birthday, averaging roughly $23.1 million per season.

* Johan Santana's deal with the Mets runs through his 34th birthday in 2013 and averages a hair over $22 million a season.

* A.J. Burnett's 5-year deal with the Yankees that averages $16.5 million runs through his 36th birthday in 2013.

* Derek Lowe signed a 4-year deal with the Braves in 2009 at $15 million per year that runs through his 39th birthday.

* Mark Buehrle signed a 4-year extension with the White Sox in 2008 that will pay him $14 million per year through his 32nd birthday.

* Ryan Dempster signed a 4-year contract with the Cubs in 2009 that will pay him $13 million per season through his 35th birthday.

Phillies general manager Ruben Amaro Jr. has made a bold decision. There is plenty of risk, and plenty of upside.

It will be interesting to watch it unfold over the next 3 years.

And one last thing . . .

Since the Phillies are trading Lee and his $9 million salary to the Mariners to help accommodate Halladay's salary, it is worth noting that the one thing standing in the way of 1 year of Halladay-Lee-Hamels might have been the 2-year contract that Jamie Moyer signed last offseason that guarantees him $8 million this season.

For more Phillies coverage and opinion, read David Murphy's blog, High Cheese, at http://go.philly.com/highcheese.