My understanding of BE bylaws is that 50% of the exit fee is due at the time that the conference departure notice is given. Without that payment the 27-month clock doesn't start ticking. The remaking 50% is due upon departure (unless other arrangements have been made). It appears that the BE withholds a portion of a school's TV and tournament revenues in escrow and applies that toward the exit fee.
Based on this understanding, I believe that Syracuse & Pitt have already paid (or made arrangements to pay) $2.5M each. Based on further announcements by the parties involved, agreement has been reached on how Syracuse & Pitt will provide the remaining $5M that each school owes to the Big East as part of their July 1, 2013 departure.
I expect that Louisville & ND have paid the BE $5M, each, and will be negotiating their additional exit fees to be able to leave the conference by July 1, 2014.
If Rutgers has not done the same then in theory, their 27-month clock has not started running. Given their financial woes, it's to be expected that they'd try to avoid or reduce payment of the exit fee. Methinks they'll insist on using disbursement of previously due exit fees toward their own payments. That would only include their share of payments from TCU, WfVU, Syracuse, Pitt & ND.