Experts estimate up to 7,000 bodies are buried on the University of Mississippi Medical Center campus. They are former patients of the state’s first mental institution, called the Insane Asylum, built in 1855, and underground radar shows their coffins stretch across 20 acres of the campus, where officials have wanted to build. But those officials have faced a steep cost — $3,000 to exhume and rebury each body, as much as $21 million total. Now UMMC is studying the cheaper alternative of handling those exhumations in-house, at a cost of $400,000 a year for at least eight years. It also would create a memorial that would preserve the remains with a visitors center and a lab that could be used to study the remains as well as the remnants of clothing and coffins.