Ticats Stadium Increased Costs

This Spec article describes what some of the extra costs are for the stadium. Some of the Ticats demands seem a bit crazy. Getting the city to build office space at the stadium to move jobs from the downtown Jarvis Street office seems like a nonstarter from the city's point of view. I'm still a bit mystified by some of the other costs being so high. Apart from renovating the North side stands, how is rebuilding 15,000 seats for the South side so expensive? How much would have a 25,000 West Harbour stadium have cost?