I have to agree that a Nussli style stadium is not nearly at the same level as the Winnipeg Blue Bombers Stadium. But there are some very expensive items in the Winnipeg Stadium that a Halifax area stadium will not require in order to host a CFL team such as:
1) my understanding is that the Winnipeg Stadium will contain a $45 million dollar recreation centre (as wespidel mentioned). Certainly a great feature but Halifax already has several recreation centres. This is probably included for the University of Manitoba students, not because it is required for a CFL team. So cut $45 million dollars from the cost.
2) Look at the roof - this is a massive structure (it looks like it extends out by about 100 feet) This roof must cost several million dollars. Halifax could get by with a much more modest roof. (not much more complex than the SMU stadium roof but over a greater circumference of the stadium).
3) Several levels of totally enclosed concourses. A great feature, but Halifax can build something simpler with only a couple of levels, and not totally enclosed.
4) I believe that I read that it will have washrooms and concessions distributed throughout the concourses. Another great feature, but would it hurt Haligonians to walk an extra 100 feet to washrooms centralized in a few areas of the stadium?
5) It has endzone seating sections on tracks than can be moved (reference - Thurmas). Again not required to host CFL games.
6) Having several seating tiers will mean that there will be many more custom make components (risers, rakers, etc.). To reduce the cost, the variety of such components should be minimized.
The Winnipeg Stadium financers (mainly the province of Manitoba taxpayers) are sparing almost no expense, but how much more will fans enjoy the games because of it? The Montreal Molson Stadium is much simpler than the Winnipeg Stadium and it seems to be a popular venue. Likewise with the Calgary McMahon Stadium which has been a good CFL venue and is a much more basic (but solid) structure.
I think it is fair to focus more on the stadiums such as the Montreal Molson Stadium and Calgary McMahon Stadium. In the long term, Halifax has a chance to match those stadiums.
I don't want to pretend that I am an expert on construction, but based on 18 months of almost obsessive study of stadium construction styles, I feel that Halifax can build a very sturdy, decent stadium for well under $100 million dollars (possibly as low as $60 million dollars for 25,000 seats that can be expanded to over 40,000). I don't think that having a stadium that can be expanded adds much to the cost (it is just a matter of leaving the endzones open and building higher along the sidelines).
Winnipeg Blue Bombers new stadium; cross-sectional drawing (source -
http://www.bluebombers.com/ , but no longer at that website)