The Saskatchewan Real Estate Commission requires a term like this to be spelled out in writing in the purchase contract, the same way it requires a commission agreement in writing, so a verbal promise does not count. The most common form here is a price reduction negotiated after a home inspection, typically $400 to $600 for the inspection itself, turns up an issue the seller had not disclosed.
A concession is not free money for the buyer, it comes out of the seller's net proceeds the same way a price cut would. Your lawyer and your REALTOR® structure the wording in the offer so the credit is applied correctly in trust accounting on closing day.
Joel Dyck negotiates concessions against what actually protects your net proceeds, not against what the buyer's agent asks for first. Get your hand-reviewed valuation from Joel Dyck.