That arrangement is legal when disclosed and consented to, but it limits what that agent can tell you. Details that would normally strengthen your negotiating position, like how motivated the seller actually is, can no longer be shared once both sides share representation.
A separate buyer's agent, at no direct cost to you in most Saskatoon transactions, gives you someone whose only job is your price and your conditions, paid from the seller's side of total closing costs of 4 to 6 percent rather than by you.
Using the listing agent can simplify logistics, but it trades away undivided advocacy to get there, which is worth weighing before you call the number on the sign. Get your hand-reviewed valuation from Joel Dyck.