The great Fred Anderson wanted to build a new stadium in Sacramento for the CFL and to bring in a MLB team but the city and state would not contribute.
$100m doesnt go as far in construction as you might think. With the concrete you have to factor in permits (never cheap, usually a percentage of total cost), steel, engineering (very not cheap!), safety and site management, seats to go on it...etc.
Winnipeg isnt getting a bargain basement stadium, but they are getting great value! Its been said before in this thread, thats about the standard, quality and price-wise, you are looking at for a new CFL stadium.
I do think its a plus for the league when these discussions are not pipe dreams!