The Saskatchewan Real Estate Commission requires written disclosure of this kind of conflict before an offer goes in, because a brokerage representing both the buyer and the seller on the same house creates a real question about whose interests are being advanced.
In practice, many brokerages resolve it by assigning a second agent inside the same office to represent the seller's side, so you keep full representation and the seller does too, and the deal still closes through a lawyer regulated by the Law Society of Saskatchewan at the usual $800 to $1,500.
Ask the question before you write the offer, not after, since the disclosure and the fix both work better ahead of a deadline. Get your hand-reviewed valuation from Joel Dyck.