Gore buillding ground floor retail rent is $14/sf and has sat empty since it opened.
http://www.bbsrealty.com/property-details/1411
100 Main E. ground floor is $16/sf and even the second floor is only $11/sf
$25.50/sf in the Lister will be a tough sell. The city will have to subsidize it (cost the taxpayers even more) by about $12-15/sf or it will sit empty. Typically the novelty of these projects is enough to at least have open full or near full occupancy to begin with, just like the Eaton Centre did in 1991-2. The fact that the spaces other than TH aren't totally finished is telling that there wasn't much interest.
By comparison, street, retail rent in First Canada Place is $33/sq. My guess is the City will eventually fill the ground floor retail with office cubes.