The financing math changes with a legal two-family home, since a lender can add a share of documented rental income to your qualifying income, which increases what you can borrow compared with a single-family purchase at the same price point. That only applies once the suite is permitted, inspected for egress and fire separation, and documented.
Ownership also means becoming a landlord under Saskatchewan's Residential Tenancies Act, with real obligations around notice periods, maintenance and rent increases, which is a meaningfully different commitment than living in a single-family home alone.
Whether a two-family home beats a single-family home for you depends on whether you actually want the landlord role, not just the extra income line, especially near the Saskatoon benchmark of $444,700. Get your hand-reviewed valuation from Joel Dyck.