One person suggested RW&Co as a place to find a black tie dress in Halifax. Although the specific dress is not confirmed, the mention of RW&Co suggests that they may carry formal or black tie attire.
Sobeys is a Canadian supermarket chain where you can find Big 8 cola, a caffeine-free zero-sugar version. Comments mention that you can find Big 8 at the Prince Street Sobeys location, which is in the heart of Halifax.