That exemption, administered by the Canada Revenue Agency, generally shields the full gain on a home that was your principal residence for every year you owned it, which matters more to most downsizers' finances than any property tax line ever will, though the sale still has to be reported.
On the moving side, Saskatchewan charges no land transfer tax, so a downsizer's actual closing costs are the Information Services Corporation transfer fee and legal fees, typically $800 to $1,500, rather than a percentage-based tax some other provinces charge on the purchase.
For someone downsizing on a deadline, knowing the real number early, on both the home being sold and the one being bought, changes the timeline more than any tax rule does. Get your hand-reviewed valuation from Joel Dyck.