CHESTNUT HILL, Mass. -- Boston College's move to join the ACC Sunday comes at a steep price for the Eagles and for a number of other schools that will be affected.

Boston College president Rev. William P. Leahy, S.J. said the Eagles joined the ACC because of the academic affiliation, the demographics of the conference that will allow the school to recruit students in the Southeast, and of course for the athletics and financial windfall that the Eagles expect will come in a 12-team conference.

But the Eagles will first have to pay to leave the Big East, and the question remains when will they depart? Leahy said he was in favor of increasing the exit fee from the Big East from $1 million to $5 million, with a 27-month advance notice. But he's not sure if the Big East has officially ratified the change. He said the Eagles would wait to see if lawyers determine that Boston College must pay the raised price instead of the $1 million price tag that Miami and Virginia Tech will pay at the end of this season to join the ACC.

Boston College athletic director Gene DeFilippo said the money, regardless of the amount, would come from the athletic department coffers, not the school's general fund. The ACC also demands an entrance fee that could be $1 million.

But the Eagles are torn as to whether they want to join the ACC for the 2004-05 or '05-06 season. Joining the ACC for next season would certainly allow for a smoother transition on the court and athletic fields because they could enjoy a lame duck Big East schedule with Miami and Virginia Tech. But changing schedules at this late stage, especially in football, could prove problematic.

The ACC wants a 12-team football championship game and might find it hard to do in time for 2004, but it is feasible. N.C. State athletic director Lee Fowler told ESPN.com on Saturday that the administrators discussed 12-team models in football and basketball during a recent meeting.

The timing of Sunday's announcement was critical for not only BC, but every other conference waiting on a decision. Leahy wanted to know about an invitation to join within the next two weeks. He said he didn't want another long drawn-out process. Leahy said there had to be an invitation and acceptance, not another round of visitations by the ACC committee on expansion.

DeFilippo said the Eagles would leave behind their NCAA Tournament units from 2001 and '02 but would gain ACC units that would make up for the loss. He wasn't sure when the Eagles would be fully vested but it is believed the Eagles could be in line to receive ACC monies in two to three years, like Miami and Virginia Tech.

The logistics of working out exit and entrance fees and scheduling needs to be resolved in the coming weeks. But the next most pressing issue for a conference is a move by the Big East.

The Big East will meet Nov. 4 in Philadelphia and was expected to announce the addition of four schools out of Conference USA -- Cincinnati and Louisville for all sports and Marquette and DePaul for everything but football. But now that plan could be dramatically altered.

Leahy said that the Big East discussed two options at a meeting earlier this month -- one with an eight- or nine-team football conference, or the 16-team model. He said there were no discussions for a 12-team football conference in the Big East as a separate league.

If the current plan sticks, then the Big East would have to add five schools in November, including three that play Division I-A football to get up to eight members for the 2005 season or '04 if Boston College leaves a year earlier. That means that Central Florida, South Florida, Marshall, Army, Navy and East Carolina are all possibilities for full membership if the Big East is searching for another football-playing member.

Meanwhile, Conference USA can't make its moves until administrators know how many members are bolting for the Big East. Conference commissioners from CUSA, Mountain West, WAC, MAC and Sun Belt were meeting Sunday at Denver's airport.

Conference USA's best hope is that the remaining football-playing Division I schools in the Big East -- Syracuse, Connecticut, Pittsburgh, Rutgers and West Virginia -- split even further apart to prevent his members joining them. A few sources Sunday said that BC's departure could prompt Syracuse and Pittsburgh to investigate if the Big Ten would have interest in a 12th team.

If the five football schools stay together, they will go after Louisville and Cincinnati to get to seven schools and then an eighth to satisfy Division I-A requirements for conference affiliation. Temple is still expected to be dropped as a football playing member from the Big East.

Conference USA, the WAC and the Mountain West have to get together to agree on who is going where over the next year. The MWC covets TCU to get to nine schools. But if TCU leaves, then Tulane and Houston could join the WAC. If TCU stays, then SMU, Rice and Tulsa could be called to replace Louisville, Cincinnati and possibly a third team that departs out of Conference USA.

The MAC offered Central Florida full membership and is trying to keep Marshall from defecting. Meanwhile, the Missouri Valley could gobble up Saint Louis and the Atlantic 10 would be interested in Charlotte if Conference USA splits apart.

The schools that are probably the most nervous right now are Southern Mississippi, UAB and Memphis, which might find a new home hard to secure unless the Sun Belt comes to their rescue.

On Sunday, BC wasn't too concerned about which division it would join in the ACC or if there would be increased costs for traveling by plane to most ACC sites for all sports. All that mattered was that the Eagles had a home and didn't have to fret about realignment anymore.

"We have secured our future for the long term,'' Leahy said. That's something that schools in the Big East, Conference USA and WAC can't comfortably say yet.

Andy Katz is a senior writer at ESPN.com.