The spread (over $1 PCL) seams a bit high to me. I doubt anybody thinks this is a high risk transaction, so I assume much of the delta is caused by arbitrage friction.
Gives a break for the small retail buyer.
As an aside, I am likely to sell some as my position is a bit much for poor me now. Undecided if it is better to short WY vs selling some PCL. Plain old alpha says short WY, but many risk and tax issues play. Confused :-)