The below prices are in CAD
Home Depot has both varieties
Porcupine 1x6x8' STK Cedar S4S Fence =$9.42
Irving 1x6x8 Knotty Eastern White Cedar =$10.20
The Lowes version of the same board
Top Choice 1 x 6 Western Red Cedar Fence Board S4S -seems to be square on all sides -$9
Interesting that the pictures show the wood square (Lowes) and rounded (HD) for the same finish S4S
Western Red Cedar Select Tight Knot Grade. This grade has a lot of personality and is used on siding , interior paneling and virtually any application. The knots and other natural features define the visual character of this grade. In this grade the knots are sound and tight.