This is how I could see a stadium proceeding.
Stage 1 would be the lower sunken bowl, mainly just seats (which might include some or all bench style seats). This would seat 13,800 (not drawn is a vehicle ramp at one end, and space under one end would have room for large changerooms and other facilities). Washrooms would also have to be included. I believe that depending on the site selected, this could be done for about $30 million. With space on the field for an additional 25,000, such a stadium could accommodate close to 39,000 for large concerts.
STAGE 1
Since Halifax would now have a stadium, exhibition CFL games and large outdoor sports events could be obtained. Once Halifax is able to obtain a large sports event (with federal funding) build the first sideline tier of seats. This would have to meet the building code and basic requirements regarding washroom fixtures and concession space. In order to have sufficient concourse space, a second concourse level would be required under that tier of seats. Concourse space for about 4 square feet per person on that side of the stadium would be required. This is considered to be a industry standard - reference
http://www.ottawa.ca/residents/publi...n_addition.pdf . That tier of seats would be built economically to minimize cost but have an interesting stadium roof design to add an aesthetically interesting feature to the stadium. The roof support is based on the Swansea Stadium in the UK (it would have to be built stronger or have a shorter roof overhang to compensate for much higher snow load requirements in the Halifax area versus the Swansea Stadium location in the UK). This would add another 8,800 seats to the 13,800 in the sunken bowl for a total of 22,600. Wheelchair locations and areas for luxury seats would be in-between the lower sunken bowl and the upper tier of seats.
STAGE 2
Now that the Halifax area would have a fair size stadium, I believe that there would be interest shown by a potential owner in obtaining a CFL team for Halifax. I think that with some temporary seating to bring the total up to 25,000, a CFL team would be viable. Once the Halifax area proves that it can support a CFL team it can obtain a Grey Cup Game. At this point, build the second sideline seating area to bring the total to 31,400. Temporary seating would also be required in the endzones to get the total to around 40,000 for the Grey Cup.
STAGE 3
Not shown is the endzone expansion to get seating up to 40,000 for the Grey Cup (which could be temporary seats) and for a potential 2034 FIFA World Mens Cup which would include Halifax as a host city (more popular than the NFL in the US and watched by billions of people). Halifax could be a first round FIFA Cup host city, and who knows, maybe even get some second round games.
I think that a stadium could be built for a construction cost that would work out to $2,500 per seat. In current dollars, a complete 31,400 stadium would be about $80 million dollars. This is not a dirt cheap outdoor stadium cost but is an economical cost estimate that is based on construction costs of many economically priced stadiums in North America and Europe. It would be important to stay within a budgeted cost. So if it can't be done for that cost then the size would have to be reduced by reducing the number of seats. However, if a CFL team is overwhelmingly popular in the Halifax area, the additional seats would be desired.