The gap between them is permits. A basement finished for family use with no suite designation just needs to be dry, code-compliant for egress and free of any water history to support its value, while a secondary suite additionally needs the City of Saskatoon's building permit for a legal second unit before a lender will credit any rental income toward a buyer's mortgage.
Both routes lose most of their value the moment the work was never permitted, since neither an automated estimate nor most appraisers can see development that has no record anywhere, and a buyer's own lender will simply treat the space as unfinished square footage regardless of how it actually looks in person.
Joel Dyck walks the space, confirms what was actually permitted, and prices the two scenarios against different comparable sets rather than one blended average. Get your hand-reviewed valuation from Joel Dyck.