Like those nine-figure contracts signed by Brett Favre and Drew Bledsoe, the 12-year, $115 million contract agreed to by Philadelphia Eagles quarterback Donovan McNabb on Friday is actually worth significantly less than advertised, but remains a blockbuster deal.

Given that McNabb will void the final three years simply by reaching some modest performance benchmarks, the contract is essentially for nine years, and two sources with knowledge of the agreement told ESPN.com that it is worth nearly $72 million.

McNabb, 25, will receive an initial signing bonus of $13.5 million and then an option bonus of $7 million in the spring of 2004. He will earn about $30 million in the first three years of the contract. The base salary for this season is $1.5 million and then base salaries are $4 million each for the following three years. They escalate after that.

"We're ecstatic . . . but we're broke," Eagles team president Joe Banner said Friday afternoon, laughing. "But if you're going to be broke, this isn't a bad guy to go broke on, right?"

Banner told ESPN.com that the team first approached McNabb and agent Fletcher Smith about a potential extension not too deep into the offseason, just after the Eagles' defeat against the St. Louis Rams in the NFC title game. To the surprise of some Philadelphia officials, the quarterback was receptive to discussions.

After taking some time in the offseason to frame their respective "levels of expectation," according to Banner, the sides began zeroing in on numbers right about the time of the regular-season opener, and then Fletcher traveled to Philadelphia this week for more substantive talks.

One of the craftiest cap managers in the league, Banner did not offer much detail into the contract. But if the structure is similar to contracts negotiated by Banner in the past -- he has many times extended the deals of key players who still had multiple years remaining on existing contracts -- it was done with an eye toward maintaining cap sanity.

McNabb's cap charge for 2002 under his original seven-year contract as a first-round choice in the 1999 draft, was to have been $5.89 million and is relatively unchanged by the extension. In fact, typical of most contracts that are negotiated by Banner, the cap value rises only gradually in future years. It is believed the cap value will not exceed more than 10 percent of the Eagles' spending limit in subsequent seasons.

With the three "voidable" seasons at the end of the deal, McNabb ostensibly will be under contract to the Eagles until he is 34, an age at which his skills might have begun to decline. Banner has demonstrated care in such matters and usually completes deals that expire at about the time a player's skills at a given position are starting to wane.

It is not unusual for the most recent megadeal quarterback contracts to have what are ostensibly "dummy" years at the end of the deal to inflate the total. The final four years of Favre's contract in Green Bay, for instance, includes base salaries totaling $50 million, money meant to artificially boost the per-year average of the overall contract.

The "voidable" years in the McNabb contract total between $43 million and $45 million.

Len Pasquarelli is a senior writer for ESPN.com.