Stonebridge is a newer south Saskatoon area built from the 2000s onward with a wide mix of condos, townhouses and single family homes, so an income unit there is often a basement suite in a fairly recent build rather than an older, informally converted space. That newer construction does not exempt the suite from permit rules.
Once permit status is confirmed, look at the suite itself: a separate entrance, an egress window sized for a bedroom, proper fire separation from the main unit, and its own heat source. A buyer's home inspection, typically $400 to $600, should specifically flag any of those that are missing.
The rent roll matters less than the paperwork behind it. Get your hand-reviewed valuation from Joel Dyck.