The cost driver is physical, not financial engineering: a typical office floor is far deeper than a typical apartment floor, so much of the interior square footage sits too far from a window to legally count as habitable space, and adding light and separate ventilation to every unit is expensive work in an existing structure.
Saskatoon's downtown office stock includes some older buildings that face exactly this problem, which is part of why conversion has stayed a one-off project rather than a program, and why the City of Saskatoon evaluates each proposal on its own building rather than under a blanket policy.
For a buyer or seller near downtown, that means judging each nearby project on its own facts rather than assuming a wave of new supply is coming, the same way a lawyer prices legal fees of $800 to $1,500 for one file rather than for the whole street. Get your hand-reviewed valuation from Joel Dyck.