Last Tuesday, Elliot “Lee” Sander, the Metropolitan Transit Authority’s new executive director, said that he would stop progress on the No. 7 extension project unless City Hall pays the $1 billion dollars in anticipated cost overruns. Originally, City Hall had allocated a mere $100 million in cost overruns, in addition to the $2 billion to be paid to bring the Flushing Line from Times Square to 11th Avenue and 34th Street as part of Mayor Michael Bloomberg’s West Side development plan. Even without this financial hitch, the project is already a year behind the original schedule, with construction currently planned for December 2007. That deadline may not be met, as City Hall is in no mood to compromise on this one. John Gallagher, a spokesman for the mayor, said that the No. 7 extension will provide the MTA with new tax revenues, implying that the added financial cost in its construction would be worth their while to assume. Adding to the No. 7 brewhaha is the $176 million necessary for the MTA to purchase 110 new subway cars.