The estimated cost is around 300 million for new tracks , small yard , 4 new/rebuilt stations , and catenary. The 104 bus is a different service corridor and a slower one. I would replace it will a Suburban Trolley service from 69th Street to 476 and the 103 as well... The remaining underused portion could be cut completed or reduced. The State has a backlog of Critical rail projects that need to be funded so those will likely go first along with the various bridge and road rebuilds...