LYNN – A developer interested in building a 156-unit residential complex on the site proposed for the new Marshall Middle School is suing the city for $6.2 million.That amount, according to a Superior Court file provided by the city solicitor?s office, represents the “…highest and best use based on actual comparable land sales” if Marlborough-based Cricket Realty Holdings was allowed to build on the proposed school?s Brookline Street site bordering the commuter rail tracks.The City Council voted 11-0 on May 14 to take the land and approved spending $1.3 million to pay Cricket for the land. The developer?s court complaint rejects that offer.?The plaintiff was offered a sum of money by the defendant as purported compensation for the taking of their property that is inadequate and does not reflect the fair market value of the property taken by the defendant,” the complaint states.The court filing is not unexpected by city attorneys and planners preparing designs for the four-story school scheduled to open in September 2016.A budget for the Marshall project discussed by planning committee members in July included $4 million for “land acquisitions” among the project costs. Two homes near the school site?s Chatham Street end are also slated to be taken.Total project costs are $92 million, according to a communication sent Friday to City Council members. The city is seeking 80 percent state reimbursement for project costs, and city officials want to ask voters when they go to the polls on Sept. 17 to allow the city to borrow $92 million “contingent upon 80 percent state reimbursement for eligible costs…” according to the communication.What exactly costs determined to be ineligible for reimbursement will be is unclear but estimates currently hover around $34 million. Those costs will be spread out much the same way a mortgage is translated into multi-year payments.City Acting Chief Financial Officer Peter Caron in July said he can assure taxpayers that borrowing associated with paying for Marshall costs not reimbursed by the state “doesn?t translate into an increase in their tax bill.”?It may affect city services supplied to that taxpayer,” he said.City Inspectional Services Director Michael Donovan this week said the city is no longer planning to keep the existing Marshall building on Porter Street standing after the new school opens in 2016.?The worst thing is to have that building deteriorating and empty,” he said.