Complex sentence: Team officials initially settled on the Autostade, which had just been built for Expo'67, but city officials balked at the cost of adding a dome and 12,000 seats, as well as demands for increased rent by the Canadian Football League's Montreal Alouettes.
Split into simpler sentences: Team officials initially settled on the Autostade, which had just been built for Expo'67. However, city officials balked at the cost of adding a dome and 12,000 seats, as well as demands for increased rent by the Canadian Football League's Montreal Alouettes.